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hsmusic-wiki - HSMusic - static wiki software cataloguing collaborative creation
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-rw-r--r--src/data/composite/control-flow/exposeConstant.js2
-rw-r--r--src/data/composite/control-flow/exposeWhetherDependencyAvailable.js42
-rw-r--r--src/data/composite/control-flow/flipFilter.js36
-rw-r--r--src/data/composite/control-flow/helpers/performAvailabilityCheck.js19
-rw-r--r--src/data/composite/control-flow/index.js3
-rw-r--r--src/data/composite/control-flow/raiseOutputWithoutDependency.js2
-rw-r--r--src/data/composite/control-flow/raiseOutputWithoutUpdateValue.js2
-rw-r--r--src/data/composite/control-flow/withAvailabilityFilter.js41
-rw-r--r--src/data/composite/control-flow/withResultOfAvailabilityCheck.js33
-rw-r--r--src/data/composite/data/excludeFromList.js5
-rw-r--r--src/data/composite/data/fillMissingListItems.js5
-rw-r--r--src/data/composite/data/index.js31
-rw-r--r--src/data/composite/data/withFilteredList.js16
-rw-r--r--src/data/composite/data/withFlattenedList.js6
-rw-r--r--src/data/composite/data/withIndexInList.js38
-rw-r--r--src/data/composite/data/withLengthOfList.js54
-rw-r--r--src/data/composite/data/withMappedList.js26
-rw-r--r--src/data/composite/data/withNearbyItemFromList.js105
-rw-r--r--src/data/composite/data/withPropertiesFromList.js6
-rw-r--r--src/data/composite/data/withPropertyFromList.js28
-rw-r--r--src/data/composite/data/withPropertyFromObject.js66
-rw-r--r--src/data/composite/data/withSortedList.js6
-rw-r--r--src/data/composite/data/withStretchedList.js36
-rw-r--r--src/data/composite/data/withSum.js33
-rw-r--r--src/data/composite/data/withUnflattenedList.js6
-rw-r--r--src/data/composite/things/album/index.js2
-rw-r--r--src/data/composite/things/album/withHasCoverArt.js64
-rw-r--r--src/data/composite/things/album/withTrackSections.js127
-rw-r--r--src/data/composite/things/album/withTracks.js46
-rw-r--r--src/data/composite/things/art-tag/index.js2
-rw-r--r--src/data/composite/things/art-tag/withAllDescendantArtTags.js44
-rw-r--r--src/data/composite/things/art-tag/withAncestorArtTagBaobabTree.js46
-rw-r--r--src/data/composite/things/artist/artistTotalDuration.js69
-rw-r--r--src/data/composite/things/artist/index.js1
-rw-r--r--src/data/composite/things/artwork/index.js5
-rw-r--r--src/data/composite/things/artwork/withAttachedArtwork.js43
-rw-r--r--src/data/composite/things/artwork/withContainingArtworkList.js46
-rw-r--r--src/data/composite/things/artwork/withContribsFromAttachedArtwork.js27
-rw-r--r--src/data/composite/things/artwork/withDate.js41
-rw-r--r--src/data/composite/things/artwork/withPropertyFromAttachedArtwork.js65
-rw-r--r--src/data/composite/things/content/contentArtists.js40
-rw-r--r--src/data/composite/things/content/hasAnnotationPart.js25
-rw-r--r--src/data/composite/things/content/helpers/withExpressedOrImplicitArtistReferences.js60
-rw-r--r--src/data/composite/things/content/index.js7
-rw-r--r--src/data/composite/things/content/withAnnotationParts.js93
-rw-r--r--src/data/composite/things/content/withHasAnnotationPart.js43
-rw-r--r--src/data/composite/things/content/withSourceText.js53
-rw-r--r--src/data/composite/things/content/withSourceURLs.js62
-rw-r--r--src/data/composite/things/content/withWebArchiveDate.js41
-rw-r--r--src/data/composite/things/contribution/index.js7
-rw-r--r--src/data/composite/things/contribution/inheritFromContributionPresets.js61
-rw-r--r--src/data/composite/things/contribution/thingPropertyMatches.js45
-rw-r--r--src/data/composite/things/contribution/thingReferenceTypeMatches.js66
-rw-r--r--src/data/composite/things/contribution/withContainingReverseContributionList.js80
-rw-r--r--src/data/composite/things/contribution/withContributionArtist.js26
-rw-r--r--src/data/composite/things/contribution/withContributionContext.js45
-rw-r--r--src/data/composite/things/contribution/withMatchingContributionPresets.js70
-rw-r--r--src/data/composite/things/flash-act/index.js1
-rw-r--r--src/data/composite/things/flash-act/withFlashSide.js22
-rw-r--r--src/data/composite/things/flash/withFlashAct.js102
-rw-r--r--src/data/composite/things/track-section/index.js3
-rw-r--r--src/data/composite/things/track-section/withAlbum.js20
-rw-r--r--src/data/composite/things/track-section/withContinueCountingFrom.js25
-rw-r--r--src/data/composite/things/track-section/withStartCountingFrom.js64
-rw-r--r--src/data/composite/things/track/index.js16
-rw-r--r--src/data/composite/things/track/inferredAdditionalNameList.js67
-rw-r--r--src/data/composite/things/track/inheritContributionListFromMainRelease.js44
-rw-r--r--src/data/composite/things/track/inheritFromMainRelease.js41
-rw-r--r--src/data/composite/things/track/inheritFromOriginalRelease.js50
-rw-r--r--src/data/composite/things/track/sharedAdditionalNameList.js38
-rw-r--r--src/data/composite/things/track/trackAdditionalNameList.js38
-rw-r--r--src/data/composite/things/track/trackReverseReferenceList.js38
-rw-r--r--src/data/composite/things/track/withAlbum.js108
-rw-r--r--src/data/composite/things/track/withAllReleases.js46
-rw-r--r--src/data/composite/things/track/withAlwaysReferenceByDirectory.js48
-rw-r--r--src/data/composite/things/track/withContainingTrackSection.js57
-rw-r--r--src/data/composite/things/track/withCoverArtistContribs.js73
-rw-r--r--src/data/composite/things/track/withDate.js34
-rw-r--r--src/data/composite/things/track/withDirectorySuffix.js36
-rw-r--r--src/data/composite/things/track/withHasUniqueCoverArt.js77
-rw-r--r--src/data/composite/things/track/withMainRelease.js (renamed from src/data/composite/things/track/withOriginalRelease.js)40
-rw-r--r--src/data/composite/things/track/withOtherReleases.js30
-rw-r--r--src/data/composite/things/track/withPropertyFromAlbum.js29
-rw-r--r--src/data/composite/things/track/withPropertyFromMainRelease.js86
-rw-r--r--src/data/composite/things/track/withSuffixDirectoryFromAlbum.js53
-rw-r--r--src/data/composite/things/track/withTrackArtDate.js60
-rw-r--r--src/data/composite/things/track/withTrackNumber.js50
-rw-r--r--src/data/composite/wiki-data/exitWithoutContribs.js1
-rw-r--r--src/data/composite/wiki-data/gobbleSoupyFind.js39
-rw-r--r--src/data/composite/wiki-data/gobbleSoupyReverse.js39
-rw-r--r--src/data/composite/wiki-data/helpers/withDirectoryFromName.js41
-rw-r--r--src/data/composite/wiki-data/helpers/withResolvedReverse.js40
-rw-r--r--src/data/composite/wiki-data/helpers/withSimpleDirectory.js52
-rw-r--r--src/data/composite/wiki-data/index.js18
-rw-r--r--src/data/composite/wiki-data/inputNotFoundMode.js9
-rw-r--r--src/data/composite/wiki-data/inputSoupyFind.js28
-rw-r--r--src/data/composite/wiki-data/inputSoupyReverse.js32
-rw-r--r--src/data/composite/wiki-data/inputWikiData.js2
-rw-r--r--src/data/composite/wiki-data/raiseResolvedReferenceList.js96
-rw-r--r--src/data/composite/wiki-data/splitContentNodesAround.js87
-rw-r--r--src/data/composite/wiki-data/withClonedThings.js68
-rw-r--r--src/data/composite/wiki-data/withConstitutedArtwork.js60
-rw-r--r--src/data/composite/wiki-data/withContentNodes.js25
-rw-r--r--src/data/composite/wiki-data/withContributionListSums.js95
-rw-r--r--src/data/composite/wiki-data/withCoverArtDate.js51
-rw-r--r--src/data/composite/wiki-data/withDirectory.js62
-rw-r--r--src/data/composite/wiki-data/withParsedCommentaryEntries.js179
-rw-r--r--src/data/composite/wiki-data/withRecontextualizedContributionList.js100
-rw-r--r--src/data/composite/wiki-data/withRedatedContributionList.js127
-rw-r--r--src/data/composite/wiki-data/withResolvedAnnotatedReferenceList.js100
-rw-r--r--src/data/composite/wiki-data/withResolvedContribs.js140
-rw-r--r--src/data/composite/wiki-data/withResolvedReference.js26
-rw-r--r--src/data/composite/wiki-data/withResolvedReferenceList.js103
-rw-r--r--src/data/composite/wiki-data/withReverseContributionList.js83
-rw-r--r--src/data/composite/wiki-data/withReverseReferenceList.js73
-rw-r--r--src/data/composite/wiki-data/withUniqueReferencingThing.js36
-rw-r--r--src/data/composite/wiki-properties/additionalFiles.js30
-rw-r--r--src/data/composite/wiki-properties/additionalNameList.js14
-rw-r--r--src/data/composite/wiki-properties/annotatedReferenceList.js64
-rw-r--r--src/data/composite/wiki-properties/commentary.js30
-rw-r--r--src/data/composite/wiki-properties/commentatorArtists.js11
-rw-r--r--src/data/composite/wiki-properties/constitutibleArtwork.js70
-rw-r--r--src/data/composite/wiki-properties/constitutibleArtworkList.js72
-rw-r--r--src/data/composite/wiki-properties/contributionList.js41
-rw-r--r--src/data/composite/wiki-properties/directory.js56
-rw-r--r--src/data/composite/wiki-properties/helpers/reference-list-helpers.js44
-rw-r--r--src/data/composite/wiki-properties/index.js13
-rw-r--r--src/data/composite/wiki-properties/referenceList.js29
-rw-r--r--src/data/composite/wiki-properties/referencedArtworkList.js31
-rw-r--r--src/data/composite/wiki-properties/reverseContributionList.js24
-rw-r--r--src/data/composite/wiki-properties/reverseReferenceList.js12
-rw-r--r--src/data/composite/wiki-properties/singleReference.js6
-rw-r--r--src/data/composite/wiki-properties/soupyFind.js14
-rw-r--r--src/data/composite/wiki-properties/soupyReverse.js37
-rw-r--r--src/data/composite/wiki-properties/thing.js40
-rw-r--r--src/data/composite/wiki-properties/thingList.js44
-rw-r--r--src/data/composite/wiki-properties/wallpaperParts.js9
137 files changed, 4544 insertions, 1454 deletions
diff --git a/src/data/composite/control-flow/exposeConstant.js b/src/data/composite/control-flow/exposeConstant.js
index e0435478..e76699c5 100644
--- a/src/data/composite/control-flow/exposeConstant.js
+++ b/src/data/composite/control-flow/exposeConstant.js
@@ -12,7 +12,7 @@ export default templateCompositeFrom({
   compose: false,
 
   inputs: {
-    value: input.staticValue(),
+    value: input.staticValue({acceptsNull: true}),
   },
 
   steps: () => [
diff --git a/src/data/composite/control-flow/exposeWhetherDependencyAvailable.js b/src/data/composite/control-flow/exposeWhetherDependencyAvailable.js
new file mode 100644
index 00000000..a2fdd6b0
--- /dev/null
+++ b/src/data/composite/control-flow/exposeWhetherDependencyAvailable.js
@@ -0,0 +1,42 @@
+// Exposes true if a dependency is available, and false otherwise,
+// or the reverse if the `negate` input is set true.
+//
+// See withResultOfAvailabilityCheck for {mode} options.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import inputAvailabilityCheckMode from './inputAvailabilityCheckMode.js';
+import withResultOfAvailabilityCheck from './withResultOfAvailabilityCheck.js';
+
+export default templateCompositeFrom({
+  annotation: `exposeWhetherDependencyAvailable`,
+
+  compose: false,
+
+  inputs: {
+    dependency: input({acceptsNull: true}),
+
+    mode: inputAvailabilityCheckMode(),
+
+    negate: input({type: 'boolean', defaultValue: false}),
+  },
+
+  steps: () => [
+    withResultOfAvailabilityCheck({
+      from: input('dependency'),
+      mode: input('mode'),
+    }),
+
+    {
+      dependencies: ['#availability', input('negate')],
+
+      compute: ({
+        ['#availability']: availability,
+        [input('negate')]: negate,
+      }) =>
+        (negate
+          ? !availability
+          : availability),
+    },
+  ],
+});
diff --git a/src/data/composite/control-flow/flipFilter.js b/src/data/composite/control-flow/flipFilter.js
new file mode 100644
index 00000000..995bacad
--- /dev/null
+++ b/src/data/composite/control-flow/flipFilter.js
@@ -0,0 +1,36 @@
+// Flips a filter, so that each true item becomes false, and vice versa.
+// Overwrites the provided dependency.
+//
+// See also:
+//  - withAvailabilityFilter
+
+import {input, templateCompositeFrom} from '#composite';
+
+export default templateCompositeFrom({
+  annotation: `flipFilter`,
+
+  inputs: {
+    filter: input({type: 'array'}),
+  },
+
+  outputs: ({
+    [input.staticDependency('filter')]: filterDependency,
+  }) => [filterDependency ?? '#flippedFilter'],
+
+  steps: () => [
+    {
+      dependencies: [
+        input('filter'),
+        input.staticDependency('filter'),
+      ],
+
+      compute: (continuation, {
+        [input('filter')]: filter,
+        [input.staticDependency('filter')]: filterDependency,
+      }) => continuation({
+        [filterDependency ?? '#flippedFilter']:
+          filter.map(item => !item),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/control-flow/helpers/performAvailabilityCheck.js b/src/data/composite/control-flow/helpers/performAvailabilityCheck.js
new file mode 100644
index 00000000..0e44ab59
--- /dev/null
+++ b/src/data/composite/control-flow/helpers/performAvailabilityCheck.js
@@ -0,0 +1,19 @@
+import {empty} from '#sugar';
+
+export default function performAvailabilityCheck(value, mode) {
+  switch (mode) {
+    case 'null':
+      return value !== undefined && value !== null;
+
+    case 'empty':
+      return value !== undefined && !empty(value);
+
+    case 'falsy':
+      return !!value && (!Array.isArray(value) || !empty(value));
+
+    case 'index':
+      return typeof value === 'number' && value >= 0;
+  }
+
+  return undefined;
+}
diff --git a/src/data/composite/control-flow/index.js b/src/data/composite/control-flow/index.js
index 7fad88b2..778dc66b 100644
--- a/src/data/composite/control-flow/index.js
+++ b/src/data/composite/control-flow/index.js
@@ -9,6 +9,9 @@ export {default as exposeConstant} from './exposeConstant.js';
 export {default as exposeDependency} from './exposeDependency.js';
 export {default as exposeDependencyOrContinue} from './exposeDependencyOrContinue.js';
 export {default as exposeUpdateValueOrContinue} from './exposeUpdateValueOrContinue.js';
+export {default as exposeWhetherDependencyAvailable} from './exposeWhetherDependencyAvailable.js';
+export {default as flipFilter} from './flipFilter.js';
 export {default as raiseOutputWithoutDependency} from './raiseOutputWithoutDependency.js';
 export {default as raiseOutputWithoutUpdateValue} from './raiseOutputWithoutUpdateValue.js';
+export {default as withAvailabilityFilter} from './withAvailabilityFilter.js';
 export {default as withResultOfAvailabilityCheck} from './withResultOfAvailabilityCheck.js';
diff --git a/src/data/composite/control-flow/raiseOutputWithoutDependency.js b/src/data/composite/control-flow/raiseOutputWithoutDependency.js
index 3d04f8a9..03d8036a 100644
--- a/src/data/composite/control-flow/raiseOutputWithoutDependency.js
+++ b/src/data/composite/control-flow/raiseOutputWithoutDependency.js
@@ -17,7 +17,7 @@ export default templateCompositeFrom({
 
   outputs: ({
     [input.staticValue('output')]: output,
-  }) => Object.keys(output ?? {}),
+  }) => Object.keys(output),
 
   steps: () => [
     withResultOfAvailabilityCheck({
diff --git a/src/data/composite/control-flow/raiseOutputWithoutUpdateValue.js b/src/data/composite/control-flow/raiseOutputWithoutUpdateValue.js
index ffa83a94..3c39f5ba 100644
--- a/src/data/composite/control-flow/raiseOutputWithoutUpdateValue.js
+++ b/src/data/composite/control-flow/raiseOutputWithoutUpdateValue.js
@@ -16,7 +16,7 @@ export default templateCompositeFrom({
 
   outputs: ({
     [input.staticValue('output')]: output,
-  }) => Object.keys(output ?? {}),
+  }) => Object.keys(output),
 
   steps: () => [
     withResultOfAvailabilityCheck({
diff --git a/src/data/composite/control-flow/withAvailabilityFilter.js b/src/data/composite/control-flow/withAvailabilityFilter.js
new file mode 100644
index 00000000..fd93af71
--- /dev/null
+++ b/src/data/composite/control-flow/withAvailabilityFilter.js
@@ -0,0 +1,41 @@
+// Performs the same availability check across all items of a list, providing
+// a list that's suitable anywhere a filter is expected.
+//
+// Accepts the same mode options as withResultOfAvailabilityCheck.
+//
+// See also:
+//  - flipFilter
+//  - withFilteredList
+//  - withResultOfAvailabilityCheck
+//
+
+import {input, templateCompositeFrom} from '#composite';
+
+import inputAvailabilityCheckMode from './inputAvailabilityCheckMode.js';
+
+import performAvailabilityCheck from './helpers/performAvailabilityCheck.js';
+
+export default templateCompositeFrom({
+  annotation: `withAvailabilityFilter`,
+
+  inputs: {
+    from: input({type: 'array'}),
+    mode: inputAvailabilityCheckMode(),
+  },
+
+  outputs: ['#availabilityFilter'],
+
+  steps: () => [
+    {
+      dependencies: [input('from'), input('mode')],
+      compute: (continuation, {
+        [input('from')]: list,
+        [input('mode')]: mode,
+      }) => continuation({
+        ['#availabilityFilter']:
+          list.map(value =>
+            performAvailabilityCheck(value, mode)),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/control-flow/withResultOfAvailabilityCheck.js b/src/data/composite/control-flow/withResultOfAvailabilityCheck.js
index a6942014..c5221a62 100644
--- a/src/data/composite/control-flow/withResultOfAvailabilityCheck.js
+++ b/src/data/composite/control-flow/withResultOfAvailabilityCheck.js
@@ -17,15 +17,18 @@
 //  - exitWithoutUpdateValue
 //  - exposeDependencyOrContinue
 //  - exposeUpdateValueOrContinue
+//  - exposeWhetherDependencyAvailable
 //  - raiseOutputWithoutDependency
 //  - raiseOutputWithoutUpdateValue
+//  - withAvailabilityFilter
 //
 
 import {input, templateCompositeFrom} from '#composite';
-import {empty} from '#sugar';
 
 import inputAvailabilityCheckMode from './inputAvailabilityCheckMode.js';
 
+import performAvailabilityCheck from './helpers/performAvailabilityCheck.js';
+
 export default templateCompositeFrom({
   annotation: `withResultOfAvailabilityCheck`,
 
@@ -39,33 +42,13 @@ export default templateCompositeFrom({
   steps: () => [
     {
       dependencies: [input('from'), input('mode')],
-
       compute: (continuation, {
         [input('from')]: value,
         [input('mode')]: mode,
-      }) => {
-        let availability;
-
-        switch (mode) {
-          case 'null':
-            availability = value !== undefined && value !== null;
-            break;
-
-          case 'empty':
-            availability = value !== undefined && !empty(value);
-            break;
-
-          case 'falsy':
-            availability = !!value && (!Array.isArray(value) || !empty(value));
-            break;
-
-          case 'index':
-            availability = typeof value === 'number' && value >= 0;
-            break;
-        }
-
-        return continuation({'#availability': availability});
-      },
+      }) => continuation({
+        ['#availability']:
+          performAvailabilityCheck(value, mode),
+      }),
     },
   ],
 });
diff --git a/src/data/composite/data/excludeFromList.js b/src/data/composite/data/excludeFromList.js
index d798dcdc..2a3e818e 100644
--- a/src/data/composite/data/excludeFromList.js
+++ b/src/data/composite/data/excludeFromList.js
@@ -5,11 +5,6 @@
 // See also:
 //  - fillMissingListItems
 //
-// More list utilities:
-//  - withFilteredList, withMappedList, withSortedList
-//  - withFlattenedList, withUnflattenedList
-//  - withPropertyFromList, withPropertiesFromList
-//
 
 import {input, templateCompositeFrom} from '#composite';
 import {empty} from '#sugar';
diff --git a/src/data/composite/data/fillMissingListItems.js b/src/data/composite/data/fillMissingListItems.js
index 4f818a79..356b1119 100644
--- a/src/data/composite/data/fillMissingListItems.js
+++ b/src/data/composite/data/fillMissingListItems.js
@@ -4,11 +4,6 @@
 // See also:
 //  - excludeFromList
 //
-// More list utilities:
-//  - withFilteredList, withMappedList, withSortedList
-//  - withFlattenedList, withUnflattenedList
-//  - withPropertyFromList, withPropertiesFromList
-//
 
 import {input, templateCompositeFrom} from '#composite';
 
diff --git a/src/data/composite/data/index.js b/src/data/composite/data/index.js
index 256c0490..05b59445 100644
--- a/src/data/composite/data/index.js
+++ b/src/data/composite/data/index.js
@@ -3,15 +3,34 @@
 // Entries here may depend on entries in #composite/control-flow.
 //
 
+// Utilities which act on generic objects
+
+export {default as withPropertiesFromObject} from './withPropertiesFromObject.js';
+export {default as withPropertyFromObject} from './withPropertyFromObject.js';
+
+// Utilities which act on generic lists
+
 export {default as excludeFromList} from './excludeFromList.js';
+
 export {default as fillMissingListItems} from './fillMissingListItems.js';
+export {default as withUniqueItemsOnly} from './withUniqueItemsOnly.js';
+
 export {default as withFilteredList} from './withFilteredList.js';
-export {default as withFlattenedList} from './withFlattenedList.js';
 export {default as withMappedList} from './withMappedList.js';
-export {default as withPropertiesFromList} from './withPropertiesFromList.js';
-export {default as withPropertiesFromObject} from './withPropertiesFromObject.js';
-export {default as withPropertyFromList} from './withPropertyFromList.js';
-export {default as withPropertyFromObject} from './withPropertyFromObject.js';
 export {default as withSortedList} from './withSortedList.js';
+export {default as withStretchedList} from './withStretchedList.js';
+
+export {default as withLengthOfList} from './withLengthOfList.js';
+export {default as withPropertyFromList} from './withPropertyFromList.js';
+export {default as withPropertiesFromList} from './withPropertiesFromList.js';
+
+export {default as withFlattenedList} from './withFlattenedList.js';
 export {default as withUnflattenedList} from './withUnflattenedList.js';
-export {default as withUniqueItemsOnly} from './withUniqueItemsOnly.js';
+
+export {default as withIndexInList} from './withIndexInList.js';
+export {default as withNearbyItemFromList} from './withNearbyItemFromList.js';
+
+// Utilities which act on slightly more particular data forms
+// (probably, containers of particular kinds of values)
+
+export {default as withSum} from './withSum.js';
diff --git a/src/data/composite/data/withFilteredList.js b/src/data/composite/data/withFilteredList.js
index 82e56903..15ee3373 100644
--- a/src/data/composite/data/withFilteredList.js
+++ b/src/data/composite/data/withFilteredList.js
@@ -2,26 +2,14 @@
 // corresponding items in a list. Items which correspond to a truthy value
 // are kept, and the rest are excluded from the output list.
 //
-// TODO: It would be neat to apply an availability check here, e.g. to allow
-// not providing a filter at all and performing the check on the contents of
-// the list (though on the filter, if present, is fine too). But that's best
-// done by some shmancy-fancy mapping support in composite.js, so a bit out
-// of reach for now (apart from proving uses built on top of a more boring
-// implementation).
-//
 // TODO: There should be two outputs - one for the items included according to
 // the filter, and one for the items excluded.
 //
 // See also:
+//  - withAvailabilityFilter
 //  - withMappedList
 //  - withSortedList
 //
-// More list utilities:
-//  - excludeFromList
-//  - fillMissingListItems
-//  - withFlattenedList, withUnflattenedList
-//  - withPropertyFromList, withPropertiesFromList
-//
 
 import {input, templateCompositeFrom} from '#composite';
 
@@ -43,7 +31,7 @@ export default templateCompositeFrom({
         [input('filter')]: filter,
       }) => continuation({
         '#filteredList':
-          list.filter((item, index) => filter[index]),
+          list.filter((_item, index) => filter[index]),
       }),
     },
   ],
diff --git a/src/data/composite/data/withFlattenedList.js b/src/data/composite/data/withFlattenedList.js
index edfa3403..31b1a742 100644
--- a/src/data/composite/data/withFlattenedList.js
+++ b/src/data/composite/data/withFlattenedList.js
@@ -5,12 +5,6 @@
 // See also:
 //  - withUnflattenedList
 //
-// More list utilities:
-//  - excludeFromList
-//  - fillMissingListItems
-//  - withFilteredList, withMappedList, withSortedList
-//  - withPropertyFromList, withPropertiesFromList
-//
 
 import {input, templateCompositeFrom} from '#composite';
 
diff --git a/src/data/composite/data/withIndexInList.js b/src/data/composite/data/withIndexInList.js
new file mode 100644
index 00000000..b1af2033
--- /dev/null
+++ b/src/data/composite/data/withIndexInList.js
@@ -0,0 +1,38 @@
+// Gets the index of the provided item in the provided list. Note that this
+// will output -1 if the item is not found, and this may be detected using
+// any availability check with type: 'index'. If the list includes the item
+// twice, the output index will be of the first match.
+//
+// Both the list and item must be provided.
+//
+// See also:
+//  - withNearbyItemFromList
+//  - exitWithoutDependency
+//  - raiseOutputWithoutDependency
+//
+
+import {input, templateCompositeFrom} from '#composite';
+
+export default templateCompositeFrom({
+  annotation: `withIndexInList`,
+
+  inputs: {
+    list: input({acceptsNull: false, type: 'array'}),
+    item: input({acceptsNull: false}),
+  },
+
+  outputs: ['#index'],
+
+  steps: () => [
+    {
+      dependencies: [input('list'), input('item')],
+      compute: (continuation, {
+        [input('list')]: list,
+        [input('item')]: item,
+      }) => continuation({
+        ['#index']:
+          list.indexOf(item),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/data/withLengthOfList.js b/src/data/composite/data/withLengthOfList.js
new file mode 100644
index 00000000..e67aa887
--- /dev/null
+++ b/src/data/composite/data/withLengthOfList.js
@@ -0,0 +1,54 @@
+import {input, templateCompositeFrom} from '#composite';
+
+function getOutputName({
+  [input.staticDependency('list')]: list,
+}) {
+  if (list && list.startsWith('#')) {
+    return `${list}.length`;
+  } else if (list) {
+    return `#${list}.length`;
+  } else {
+    return '#length';
+  }
+}
+
+export default templateCompositeFrom({
+  annotation: `withMappedList`,
+
+  inputs: {
+    list: input({type: 'array'}),
+  },
+
+  outputs: inputs => [getOutputName(inputs)],
+
+  steps: () => [
+    {
+      dependencies: [input.staticDependency('list')],
+      compute: (continuation, inputs) =>
+        continuation({'#output': getOutputName(inputs)}),
+    },
+
+    {
+      dependencies: [input('list')],
+      compute: (continuation, {
+        [input('list')]: list,
+      }) => continuation({
+        ['#value']:
+          (list === null
+            ? null
+            : list.length),
+      }),
+    },
+
+    {
+      dependencies: ['#output', '#value'],
+
+      compute: (continuation, {
+        ['#output']: output,
+        ['#value']: value,
+      }) => continuation({
+        [output]: value,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/data/withMappedList.js b/src/data/composite/data/withMappedList.js
index e0a700b2..cd32058e 100644
--- a/src/data/composite/data/withMappedList.js
+++ b/src/data/composite/data/withMappedList.js
@@ -1,18 +1,16 @@
 // Applies a map function to each item in a list, just like a normal JavaScript
 // map.
 //
+// Pass a filter (e.g. from withAvailabilityFilter) to process only items
+// kept by the filter. Other items will be left as-is.
+//
 // See also:
 //  - withFilteredList
 //  - withSortedList
 //
-// More list utilities:
-//  - excludeFromList
-//  - fillMissingListItems
-//  - withFlattenedList, withUnflattenedList
-//  - withPropertyFromList, withPropertiesFromList
-//
 
 import {input, templateCompositeFrom} from '#composite';
+import {stitchArrays} from '#sugar';
 
 export default templateCompositeFrom({
   annotation: `withMappedList`,
@@ -20,19 +18,31 @@ export default templateCompositeFrom({
   inputs: {
     list: input({type: 'array'}),
     map: input({type: 'function'}),
+
+    filter: input({
+      type: 'array',
+      defaultValue: null,
+    }),
   },
 
   outputs: ['#mappedList'],
 
   steps: () => [
     {
-      dependencies: [input('list'), input('map')],
+      dependencies: [input('list'), input('map'), input('filter')],
       compute: (continuation, {
         [input('list')]: list,
         [input('map')]: mapFn,
+        [input('filter')]: filter,
       }) => continuation({
         ['#mappedList']:
-          list.map(mapFn),
+          stitchArrays({
+            item: list,
+            keep: filter ?? Array.from(list, () => true),
+          }).map(({item, keep}, index) =>
+              (keep
+                ? mapFn(item, index, list)
+                : item)),
       }),
     },
   ],
diff --git a/src/data/composite/data/withNearbyItemFromList.js b/src/data/composite/data/withNearbyItemFromList.js
new file mode 100644
index 00000000..5e165219
--- /dev/null
+++ b/src/data/composite/data/withNearbyItemFromList.js
@@ -0,0 +1,105 @@
+// Gets a nearby (typically adjacent) item in a list, meaning the item which is
+// placed at a particular offset compared to the provided item. This is null if
+// the provided list doesn't include the provided item at all, and also if the
+// offset would read past either end of the list - except if configured:
+//
+//  - If the 'wrap' input is provided (as true), the offset will loop around
+//    and continue from the opposing end.
+//
+//  - If the 'valuePastEdge' input is provided, that value will be output
+//    instead of null.
+//
+//  - If the 'filter' input is provided, corresponding items will be skipped,
+//    and only (repeating `offset`) the next included in the filter will be
+//    returned.
+//
+// Both the list and item must be provided.
+//
+// See also:
+//  - withIndexInList
+//
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+import withIndexInList from './withIndexInList.js';
+
+export default templateCompositeFrom({
+  annotation: `withNearbyItemFromList`,
+
+  inputs: {
+    list: input({acceptsNull: false, type: 'array'}),
+    item: input({acceptsNull: false}),
+    offset: input({type: 'number'}),
+
+    wrap: input({type: 'boolean', defaultValue: false}),
+    valuePastEdge: input({defaultValue: null}),
+
+    filter: input({defaultValue: null, type: 'array'}),
+  },
+
+  outputs: ['#nearbyItem'],
+
+  steps: () => [
+    withIndexInList({
+      list: input('list'),
+      item: input('item'),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#index',
+      mode: input.value('index'),
+
+      output: input.value({'#nearbyItem': null}),
+    }),
+
+    {
+      dependencies: [
+        input('list'),
+        input('offset'),
+
+        input('wrap'),
+        input('valuePastEdge'),
+
+        input('filter'),
+
+        '#index',
+      ],
+
+      compute: (continuation, {
+        [input('list')]: list,
+        [input('offset')]: offset,
+
+        [input('wrap')]: wrap,
+        [input('valuePastEdge')]: valuePastEdge,
+
+        [input('filter')]: filter,
+
+        ['#index']: index,
+      }) => {
+        const startIndex = index;
+
+        do {
+          index += offset;
+
+          if (wrap) {
+            index = index % list.length;
+          } else if (index < 0) {
+            return continuation({'#nearbyItem': valuePastEdge});
+          } else if (index >= list.length) {
+            return continuation({'#nearbyItem': valuePastEdge});
+          }
+
+          if (filter && !filter[index]) {
+            continue;
+          }
+
+          return continuation({'#nearbyItem': list[index]});
+        } while (index !== startIndex);
+
+        return continuation({'#nearbyItem': null});
+      },
+    },
+  ],
+});
diff --git a/src/data/composite/data/withPropertiesFromList.js b/src/data/composite/data/withPropertiesFromList.js
index 08907bab..fb4134bc 100644
--- a/src/data/composite/data/withPropertiesFromList.js
+++ b/src/data/composite/data/withPropertiesFromList.js
@@ -8,12 +8,6 @@
 //  - withPropertiesFromObject
 //  - withPropertyFromList
 //
-// More list utilities:
-//  - excludeFromList
-//  - fillMissingListItems
-//  - withFilteredList, withMappedList, withSortedList
-//  - withFlattenedList, withUnflattenedList
-//
 
 import {input, templateCompositeFrom} from '#composite';
 import {isString, validateArrayItems} from '#validators';
diff --git a/src/data/composite/data/withPropertyFromList.js b/src/data/composite/data/withPropertyFromList.js
index a2c66d77..760095c2 100644
--- a/src/data/composite/data/withPropertyFromList.js
+++ b/src/data/composite/data/withPropertyFromList.js
@@ -5,17 +5,15 @@
 // original list are kept null here. Objects which don't have the specified
 // property are retained in-place as null.
 //
+// If the `internal` input is true, this reads the CacheableObject update value
+// of each object rather than its exposed value.
+//
 // See also:
 //  - withPropertiesFromList
 //  - withPropertyFromObject
 //
-// More list utilities:
-//  - excludeFromList
-//  - fillMissingListItems
-//  - withFilteredList, withMappedList, withSortedList
-//  - withFlattenedList, withUnflattenedList
-//
 
+import CacheableObject from '#cacheable-object';
 import {input, templateCompositeFrom} from '#composite';
 
 function getOutputName({list, property, prefix}) {
@@ -32,6 +30,7 @@ export default templateCompositeFrom({
     list: input({type: 'array'}),
     property: input({type: 'string'}),
     prefix: input.staticValue({type: 'string', defaultValue: null}),
+    internal: input({type: 'boolean', defaultValue: false}),
   },
 
   outputs: ({
@@ -43,13 +42,26 @@ export default templateCompositeFrom({
 
   steps: () => [
     {
-      dependencies: [input('list'), input('property')],
+      dependencies: [
+        input('list'),
+        input('property'),
+        input('internal'),
+      ],
+
       compute: (continuation, {
         [input('list')]: list,
         [input('property')]: property,
+        [input('internal')]: internal,
       }) => continuation({
         ['#values']:
-          list.map(item => item[property] ?? null),
+          list.map(item =>
+            (item === null
+              ? null
+           : internal
+              ? CacheableObject.getUpdateValue(item, property)
+                  ?? null
+              : item[property]
+                  ?? null)),
       }),
     },
 
diff --git a/src/data/composite/data/withPropertyFromObject.js b/src/data/composite/data/withPropertyFromObject.js
index b31bab15..7b452b99 100644
--- a/src/data/composite/data/withPropertyFromObject.js
+++ b/src/data/composite/data/withPropertyFromObject.js
@@ -2,30 +2,42 @@
 // If the object itself is null, or the object doesn't have the listed property,
 // the provided dependency will also be null.
 //
+// If the `internal` input is true, this reads the CacheableObject update value
+// of the object rather than its exposed value.
+//
 // See also:
 //  - withPropertiesFromObject
 //  - withPropertyFromList
 //
 
+import CacheableObject from '#cacheable-object';
 import {input, templateCompositeFrom} from '#composite';
 
+function getOutputName({
+  [input.staticDependency('object')]: object,
+  [input.staticValue('property')]: property,
+}) {
+  if (object && property) {
+    if (object.startsWith('#')) {
+      return `${object}.${property}`;
+    } else {
+      return `#${object}.${property}`;
+    }
+  } else {
+    return '#value';
+  }
+}
+
 export default templateCompositeFrom({
   annotation: `withPropertyFromObject`,
 
   inputs: {
     object: input({type: 'object', acceptsNull: true}),
     property: input({type: 'string'}),
+    internal: input({type: 'boolean', defaultValue: false}),
   },
 
-  outputs: ({
-    [input.staticDependency('object')]: object,
-    [input.staticValue('property')]: property,
-  }) =>
-    (object && property
-      ? (object.startsWith('#')
-          ? [`${object}.${property}`]
-          : [`#${object}.${property}`])
-      : ['#value']),
+  outputs: inputs => [getOutputName(inputs)],
 
   steps: () => [
     {
@@ -34,35 +46,41 @@ export default templateCompositeFrom({
         input.staticValue('property'),
       ],
 
-      compute: (continuation, {
-        [input.staticDependency('object')]: object,
-        [input.staticValue('property')]: property,
-      }) => continuation({
-        '#output':
-          (object && property
-            ? (object.startsWith('#')
-                ? `${object}.${property}`
-                : `#${object}.${property}`)
-            : '#value'),
-      }),
+      compute: (continuation, inputs) =>
+        continuation({'#output': getOutputName(inputs)}),
     },
 
     {
       dependencies: [
-        '#output',
         input('object'),
         input('property'),
+        input('internal'),
       ],
 
       compute: (continuation, {
-        ['#output']: output,
         [input('object')]: object,
         [input('property')]: property,
+        [input('internal')]: internal,
       }) => continuation({
-        [output]:
+        '#value':
           (object === null
             ? null
-            : object[property] ?? null),
+         : internal
+            ? CacheableObject.getUpdateValue(object, property)
+                ?? null
+            : object[property]
+                ?? null),
+      }),
+    },
+
+    {
+      dependencies: ['#output', '#value'],
+
+      compute: (continuation, {
+        ['#output']: output,
+        ['#value']: value,
+      }) => continuation({
+        [output]: value,
       }),
     },
   ],
diff --git a/src/data/composite/data/withSortedList.js b/src/data/composite/data/withSortedList.js
index dd810786..a7d21768 100644
--- a/src/data/composite/data/withSortedList.js
+++ b/src/data/composite/data/withSortedList.js
@@ -27,12 +27,6 @@
 //  - withFilteredList
 //  - withMappedList
 //
-// More list utilities:
-//  - excludeFromList
-//  - fillMissingListItems
-//  - withFlattenedList, withUnflattenedList
-//  - withPropertyFromList, withPropertiesFromList
-//
 
 import {input, templateCompositeFrom} from '#composite';
 
diff --git a/src/data/composite/data/withStretchedList.js b/src/data/composite/data/withStretchedList.js
new file mode 100644
index 00000000..46733064
--- /dev/null
+++ b/src/data/composite/data/withStretchedList.js
@@ -0,0 +1,36 @@
+// Repeats each item in a list in-place by a corresponding length.
+
+import {input, templateCompositeFrom} from '#composite';
+import {repeat, stitchArrays} from '#sugar';
+import {isNumber, validateArrayItems} from '#validators';
+
+export default templateCompositeFrom({
+  annotation: `withStretchedList`,
+
+  inputs: {
+    list: input({type: 'array'}),
+
+    lengths: input({
+      validate: validateArrayItems(isNumber),
+    }),
+  },
+
+  outputs: ['#stretchedList'],
+
+  steps: () => [
+    {
+      dependencies: [input('list'), input('lengths')],
+      compute: (continuation, {
+        [input('list')]: list,
+        [input('lengths')]: lengths,
+      }) => continuation({
+        ['#stretchedList']:
+          stitchArrays({
+            item: list,
+            length: lengths,
+          }).map(({item, length}) => repeat(length, [item]))
+            .flat(),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/data/withSum.js b/src/data/composite/data/withSum.js
new file mode 100644
index 00000000..484e9906
--- /dev/null
+++ b/src/data/composite/data/withSum.js
@@ -0,0 +1,33 @@
+// Gets the numeric total of adding all the values in a list together.
+// Values that are false, null, or undefined are skipped over.
+
+import {input, templateCompositeFrom} from '#composite';
+import {isNumber, sparseArrayOf} from '#validators';
+
+export default templateCompositeFrom({
+  annotation: `withSum`,
+
+  inputs: {
+    values: input({
+      validate: sparseArrayOf(isNumber),
+    }),
+  },
+
+  outputs: ['#sum'],
+
+  steps: () => [
+    {
+      dependencies: [input('values')],
+      compute: (continuation, {
+        [input('values')]: values,
+      }) => continuation({
+        ['#sum']:
+          values
+            .filter(item => typeof item === 'number')
+            .reduce(
+              (accumulator, value) => accumulator + value,
+              0),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/data/withUnflattenedList.js b/src/data/composite/data/withUnflattenedList.js
index 39a666dc..820d628a 100644
--- a/src/data/composite/data/withUnflattenedList.js
+++ b/src/data/composite/data/withUnflattenedList.js
@@ -7,12 +7,6 @@
 // See also:
 //  - withFlattenedList
 //
-// More list utilities:
-//  - excludeFromList
-//  - fillMissingListItems
-//  - withFilteredList, withMappedList, withSortedList
-//  - withPropertyFromList, withPropertiesFromList
-//
 
 import {input, templateCompositeFrom} from '#composite';
 import {isWholeNumber, validateArrayItems} from '#validators';
diff --git a/src/data/composite/things/album/index.js b/src/data/composite/things/album/index.js
index 8139f10e..dfc6864f 100644
--- a/src/data/composite/things/album/index.js
+++ b/src/data/composite/things/album/index.js
@@ -1,2 +1,2 @@
+export {default as withHasCoverArt} from './withHasCoverArt.js';
 export {default as withTracks} from './withTracks.js';
-export {default as withTrackSections} from './withTrackSections.js';
diff --git a/src/data/composite/things/album/withHasCoverArt.js b/src/data/composite/things/album/withHasCoverArt.js
new file mode 100644
index 00000000..fd3f2894
--- /dev/null
+++ b/src/data/composite/things/album/withHasCoverArt.js
@@ -0,0 +1,64 @@
+// TODO: This shouldn't be coded as an Album-specific thing,
+// or even really to do with cover artworks in particular, either.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency, withResultOfAvailabilityCheck}
+  from '#composite/control-flow';
+import {fillMissingListItems, withFlattenedList, withPropertyFromList}
+  from '#composite/data';
+
+export default templateCompositeFrom({
+  annotation: 'withHasCoverArt',
+
+  outputs: ['#hasCoverArt'],
+
+  steps: () => [
+    withResultOfAvailabilityCheck({
+      from: 'coverArtistContribs',
+      mode: input.value('empty'),
+    }),
+
+    {
+      dependencies: ['#availability'],
+      compute: (continuation, {
+        ['#availability']: availability,
+      }) =>
+        (availability
+          ? continuation.raiseOutput({
+              ['#hasCoverArt']: true,
+            })
+          : continuation()),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: 'coverArtworks',
+      mode: input.value('empty'),
+      output: input.value({'#hasCoverArt': false}),
+    }),
+
+    withPropertyFromList({
+      list: 'coverArtworks',
+      property: input.value('artistContribs'),
+      internal: input.value(true),
+    }),
+
+    // Since we're getting the update value for each artwork's artistContribs,
+    // it may not be set at all, and in that case won't be exposing as [].
+    fillMissingListItems({
+      list: '#coverArtworks.artistContribs',
+      fill: input.value([]),
+    }),
+
+    withFlattenedList({
+      list: '#coverArtworks.artistContribs',
+    }),
+
+    withResultOfAvailabilityCheck({
+      from: '#flattenedList',
+      mode: input.value('empty'),
+    }).outputs({
+      '#availability': '#hasCoverArt',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/album/withTrackSections.js b/src/data/composite/things/album/withTrackSections.js
deleted file mode 100644
index 0a1ebebc..00000000
--- a/src/data/composite/things/album/withTrackSections.js
+++ /dev/null
@@ -1,127 +0,0 @@
-import {input, templateCompositeFrom} from '#composite';
-import find from '#find';
-import {empty, filterMultipleArrays, stitchArrays} from '#sugar';
-import {isTrackSectionList} from '#validators';
-
-import {exitWithoutDependency, exitWithoutUpdateValue}
-  from '#composite/control-flow';
-import {withResolvedReferenceList} from '#composite/wiki-data';
-
-import {
-  fillMissingListItems,
-  withFlattenedList,
-  withPropertiesFromList,
-  withUnflattenedList,
-} from '#composite/data';
-
-export default templateCompositeFrom({
-  annotation: `withTrackSections`,
-
-  outputs: ['#trackSections'],
-
-  steps: () => [
-    exitWithoutDependency({
-      dependency: 'ownTrackData',
-      value: input.value([]),
-    }),
-
-    exitWithoutUpdateValue({
-      mode: input.value('empty'),
-      value: input.value([]),
-    }),
-
-    // TODO: input.updateValue description down here is a kludge.
-    withPropertiesFromList({
-      list: input.updateValue({
-        validate: isTrackSectionList,
-      }),
-      prefix: input.value('#sections'),
-      properties: input.value([
-        'tracks',
-        'dateOriginallyReleased',
-        'isDefaultTrackSection',
-        'name',
-        'color',
-      ]),
-    }),
-
-    fillMissingListItems({
-      list: '#sections.tracks',
-      fill: input.value([]),
-    }),
-
-    fillMissingListItems({
-      list: '#sections.isDefaultTrackSection',
-      fill: input.value(false),
-    }),
-
-    fillMissingListItems({
-      list: '#sections.name',
-      fill: input.value('Unnamed Track Section'),
-    }),
-
-    fillMissingListItems({
-      list: '#sections.color',
-      fill: input.dependency('color'),
-    }),
-
-    withFlattenedList({
-      list: '#sections.tracks',
-    }).outputs({
-      ['#flattenedList']: '#trackRefs',
-      ['#flattenedIndices']: '#sections.startIndex',
-    }),
-
-    withResolvedReferenceList({
-      list: '#trackRefs',
-      data: 'ownTrackData',
-      notFoundMode: input.value('null'),
-      find: input.value(find.track),
-    }).outputs({
-      ['#resolvedReferenceList']: '#tracks',
-    }),
-
-    withUnflattenedList({
-      list: '#tracks',
-      indices: '#sections.startIndex',
-    }).outputs({
-      ['#unflattenedList']: '#sections.tracks',
-    }),
-
-    {
-      dependencies: [
-        '#sections.tracks',
-        '#sections.name',
-        '#sections.color',
-        '#sections.dateOriginallyReleased',
-        '#sections.isDefaultTrackSection',
-        '#sections.startIndex',
-      ],
-
-      compute: (continuation, {
-        '#sections.tracks': tracks,
-        '#sections.name': name,
-        '#sections.color': color,
-        '#sections.dateOriginallyReleased': dateOriginallyReleased,
-        '#sections.isDefaultTrackSection': isDefaultTrackSection,
-        '#sections.startIndex': startIndex,
-      }) => {
-        filterMultipleArrays(
-          tracks, name, color, dateOriginallyReleased, isDefaultTrackSection, startIndex,
-          tracks => !empty(tracks));
-
-        return continuation({
-          ['#trackSections']:
-            stitchArrays({
-              tracks,
-              name,
-              color,
-              dateOriginallyReleased,
-              isDefaultTrackSection,
-              startIndex,
-            }),
-        });
-      },
-    },
-  ],
-});
diff --git a/src/data/composite/things/album/withTracks.js b/src/data/composite/things/album/withTracks.js
index fff3d5ae..835ee570 100644
--- a/src/data/composite/things/album/withTracks.js
+++ b/src/data/composite/things/album/withTracks.js
@@ -1,9 +1,8 @@
 import {input, templateCompositeFrom} from '#composite';
-import find from '#find';
 
-import {exitWithoutDependency, raiseOutputWithoutDependency}
-  from '#composite/control-flow';
-import {withResolvedReferenceList} from '#composite/wiki-data';
+import {withFlattenedList, withPropertyFromList} from '#composite/data';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
 
 export default templateCompositeFrom({
   annotation: `withTracks`,
@@ -11,41 +10,20 @@ export default templateCompositeFrom({
   outputs: ['#tracks'],
 
   steps: () => [
-    exitWithoutDependency({
-      dependency: 'ownTrackData',
-      value: input.value([]),
-    }),
-
     raiseOutputWithoutDependency({
       dependency: 'trackSections',
-      mode: input.value('empty'),
-      output: input.value({
-        ['#tracks']: [],
-      }),
+      output: input.value({'#tracks': []}),
     }),
 
-    {
-      dependencies: ['trackSections'],
-      compute: (continuation, {trackSections}) =>
-        continuation({
-          '#trackRefs': trackSections
-            .flatMap(section => section.tracks ?? []),
-        }),
-    },
-
-    withResolvedReferenceList({
-      list: '#trackRefs',
-      data: 'ownTrackData',
-      find: input.value(find.track),
+    withPropertyFromList({
+      list: 'trackSections',
+      property: input.value('tracks'),
     }),
 
-    {
-      dependencies: ['#resolvedReferenceList'],
-      compute: (continuation, {
-        ['#resolvedReferenceList']: resolvedReferenceList,
-      }) => continuation({
-        ['#tracks']: resolvedReferenceList,
-      })
-    },
+    withFlattenedList({
+      list: '#trackSections.tracks',
+    }).outputs({
+      ['#flattenedList']: '#tracks',
+    }),
   ],
 });
diff --git a/src/data/composite/things/art-tag/index.js b/src/data/composite/things/art-tag/index.js
new file mode 100644
index 00000000..bbd38293
--- /dev/null
+++ b/src/data/composite/things/art-tag/index.js
@@ -0,0 +1,2 @@
+export {default as withAllDescendantArtTags} from './withAllDescendantArtTags.js';
+export {default as withAncestorArtTagBaobabTree} from './withAncestorArtTagBaobabTree.js';
diff --git a/src/data/composite/things/art-tag/withAllDescendantArtTags.js b/src/data/composite/things/art-tag/withAllDescendantArtTags.js
new file mode 100644
index 00000000..795f96cd
--- /dev/null
+++ b/src/data/composite/things/art-tag/withAllDescendantArtTags.js
@@ -0,0 +1,44 @@
+// Gets all the art tags which descend from this one - that means its own direct
+// descendants, but also all the direct and indirect desceands of each of those!
+// The results aren't specially sorted, but they won't contain any duplicates
+// (for example if two descendant tags both route deeper to end up including
+// some of the same tags).
+
+import {input, templateCompositeFrom} from '#composite';
+import {unique} from '#sugar';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withResolvedReferenceList} from '#composite/wiki-data';
+import {soupyFind} from '#composite/wiki-properties';
+
+export default templateCompositeFrom({
+  annotation: `withAllDescendantArtTags`,
+
+  outputs: ['#allDescendantArtTags'],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: 'directDescendantArtTags',
+      mode: input.value('empty'),
+      output: input.value({'#allDescendantArtTags': []})
+    }),
+
+    withResolvedReferenceList({
+      list: 'directDescendantArtTags',
+      find: soupyFind.input('artTag'),
+    }),
+
+    {
+      dependencies: ['#resolvedReferenceList'],
+      compute: (continuation, {
+        ['#resolvedReferenceList']: directDescendantArtTags,
+      }) => continuation({
+        ['#allDescendantArtTags']:
+          unique([
+            ...directDescendantArtTags,
+            ...directDescendantArtTags.flatMap(artTag => artTag.allDescendantArtTags),
+          ]),
+      }),
+    },
+  ],
+})
diff --git a/src/data/composite/things/art-tag/withAncestorArtTagBaobabTree.js b/src/data/composite/things/art-tag/withAncestorArtTagBaobabTree.js
new file mode 100644
index 00000000..e084a42b
--- /dev/null
+++ b/src/data/composite/things/art-tag/withAncestorArtTagBaobabTree.js
@@ -0,0 +1,46 @@
+// Gets all the art tags which are ancestors of this one as a "baobab tree" -
+// what you'd typically think of as roots are all up in the air! Since this
+// really is backwards from the way that the art tag tree is written in data,
+// chances are pretty good that there will be many of the exact same "leaf"
+// nodes - art tags which don't themselves have any ancestors. In the actual
+// data structure, each node is a Map, with keys for each ancestor and values
+// for each ancestor's own baobab (thus a branching structure, just like normal
+// trees in this regard).
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withReverseReferenceList} from '#composite/wiki-data';
+import {soupyReverse} from '#composite/wiki-properties';
+
+export default templateCompositeFrom({
+  annotation: `withAncestorArtTagBaobabTree`,
+
+  outputs: ['#ancestorArtTagBaobabTree'],
+
+  steps: () => [
+    withReverseReferenceList({
+      reverse: soupyReverse.input('artTagsWhichDirectlyAncestor'),
+    }).outputs({
+      ['#reverseReferenceList']: '#directAncestorArtTags',
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#directAncestorArtTags',
+      mode: input.value('empty'),
+      output: input.value({'#ancestorArtTagBaobabTree': new Map()}),
+    }),
+
+    {
+      dependencies: ['#directAncestorArtTags'],
+      compute: (continuation, {
+        ['#directAncestorArtTags']: directAncestorArtTags,
+      }) => continuation({
+        ['#ancestorArtTagBaobabTree']:
+          new Map(
+            directAncestorArtTags
+              .map(artTag => [artTag, artTag.ancestorArtTagBaobabTree])),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/artist/artistTotalDuration.js b/src/data/composite/things/artist/artistTotalDuration.js
new file mode 100644
index 00000000..b8a205fe
--- /dev/null
+++ b/src/data/composite/things/artist/artistTotalDuration.js
@@ -0,0 +1,69 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {exposeDependency} from '#composite/control-flow';
+import {withFilteredList, withPropertyFromList} from '#composite/data';
+import {withContributionListSums, withReverseReferenceList}
+  from '#composite/wiki-data';
+import {soupyReverse} from '#composite/wiki-properties';
+
+export default templateCompositeFrom({
+  annotation: `artistTotalDuration`,
+
+  compose: false,
+
+  steps: () => [
+    withReverseReferenceList({
+      reverse: soupyReverse.input('trackArtistContributionsBy'),
+    }).outputs({
+      '#reverseReferenceList': '#contributionsAsArtist',
+    }),
+
+    withReverseReferenceList({
+      reverse: soupyReverse.input('trackContributorContributionsBy'),
+    }).outputs({
+      '#reverseReferenceList': '#contributionsAsContributor',
+    }),
+
+    {
+      dependencies: [
+        '#contributionsAsArtist',
+        '#contributionsAsContributor',
+      ],
+
+      compute: (continuation, {
+        ['#contributionsAsArtist']: artistContribs,
+        ['#contributionsAsContributor']: contributorContribs,
+      }) => continuation({
+        ['#allContributions']: [
+          ...artistContribs,
+          ...contributorContribs,
+        ],
+      }),
+    },
+
+    withPropertyFromList({
+      list: '#allContributions',
+      property: input.value('thing'),
+    }),
+
+    withPropertyFromList({
+      list: '#allContributions.thing',
+      property: input.value('isMainRelease'),
+    }),
+
+    withFilteredList({
+      list: '#allContributions',
+      filter: '#allContributions.thing.isMainRelease',
+    }).outputs({
+      '#filteredList': '#mainReleaseContributions',
+    }),
+
+    withContributionListSums({
+      list: '#mainReleaseContributions',
+    }),
+
+    exposeDependency({
+      dependency: '#contributionListDuration',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/artist/index.js b/src/data/composite/things/artist/index.js
new file mode 100644
index 00000000..55514c71
--- /dev/null
+++ b/src/data/composite/things/artist/index.js
@@ -0,0 +1 @@
+export {default as artistTotalDuration} from './artistTotalDuration.js';
diff --git a/src/data/composite/things/artwork/index.js b/src/data/composite/things/artwork/index.js
new file mode 100644
index 00000000..3693c10f
--- /dev/null
+++ b/src/data/composite/things/artwork/index.js
@@ -0,0 +1,5 @@
+export {default as withAttachedArtwork} from './withAttachedArtwork.js';
+export {default as withContainingArtworkList} from './withContainingArtworkList.js';
+export {default as withContribsFromAttachedArtwork} from './withContribsFromAttachedArtwork.js';
+export {default as withDate} from './withDate.js';
+export {default as withPropertyFromAttachedArtwork} from './withPropertyFromAttachedArtwork.js';
diff --git a/src/data/composite/things/artwork/withAttachedArtwork.js b/src/data/composite/things/artwork/withAttachedArtwork.js
new file mode 100644
index 00000000..d7c0d87b
--- /dev/null
+++ b/src/data/composite/things/artwork/withAttachedArtwork.js
@@ -0,0 +1,43 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {flipFilter, raiseOutputWithoutDependency}
+  from '#composite/control-flow';
+import {withNearbyItemFromList, withPropertyFromList} from '#composite/data';
+
+import withContainingArtworkList from './withContainingArtworkList.js';
+
+export default templateCompositeFrom({
+  annotaion: `withContribsFromMainArtwork`,
+
+  outputs: ['#attachedArtwork'],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: 'attachAbove',
+      mode: input.value('falsy'),
+      output: input.value({'#attachedArtwork': null}),
+    }),
+
+    withContainingArtworkList(),
+
+    withPropertyFromList({
+      list: '#containingArtworkList',
+      property: input.value('attachAbove'),
+    }),
+
+    flipFilter({
+      filter: '#containingArtworkList.attachAbove',
+    }).outputs({
+      '#containingArtworkList.attachAbove': '#filterNotAttached',
+    }),
+
+    withNearbyItemFromList({
+      list: '#containingArtworkList',
+      item: input.myself(),
+      offset: input.value(-1),
+      filter: '#filterNotAttached',
+    }).outputs({
+      '#nearbyItem': '#attachedArtwork',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/artwork/withContainingArtworkList.js b/src/data/composite/things/artwork/withContainingArtworkList.js
new file mode 100644
index 00000000..9c928ffd
--- /dev/null
+++ b/src/data/composite/things/artwork/withContainingArtworkList.js
@@ -0,0 +1,46 @@
+// Gets the list of artworks which contains this one, which is functionally
+// equivalent to `this.thing[this.thingProperty]`. If the exposed value is not
+// a list at all (i.e. the property holds a single artwork), this composition
+// outputs null.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+
+export default templateCompositeFrom({
+  annotation: `withContainingArtworkList`,
+
+  outputs: ['#containingArtworkList'],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: 'thing',
+      output: input.value({'#containingArtworkList': null}),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: 'thingProperty',
+      output: input.value({'#containingArtworkList': null}),
+    }),
+
+    withPropertyFromObject({
+      object: 'thing',
+      property: 'thingProperty',
+    }).outputs({
+      '#value': '#containingValue',
+    }),
+
+    {
+      dependencies: ['#containingValue'],
+      compute: (continuation, {
+        ['#containingValue']: containingValue,
+      }) => continuation({
+        ['#containingArtworkList']:
+          (Array.isArray(containingValue)
+            ? containingValue
+            : null),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/artwork/withContribsFromAttachedArtwork.js b/src/data/composite/things/artwork/withContribsFromAttachedArtwork.js
new file mode 100644
index 00000000..e9425c95
--- /dev/null
+++ b/src/data/composite/things/artwork/withContribsFromAttachedArtwork.js
@@ -0,0 +1,27 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withRecontextualizedContributionList} from '#composite/wiki-data';
+
+import withPropertyFromAttachedArtwork from './withPropertyFromAttachedArtwork.js';
+
+export default templateCompositeFrom({
+  annotaion: `withContribsFromAttachedArtwork`,
+
+  outputs: ['#attachedArtwork.artistContribs'],
+
+  steps: () => [
+    withPropertyFromAttachedArtwork({
+      property: input.value('artistContribs'),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#attachedArtwork.artistContribs',
+      output: input.value({'#attachedArtwork.artistContribs': null}),
+    }),
+
+    withRecontextualizedContributionList({
+      list: '#attachedArtwork.artistContribs',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/artwork/withDate.js b/src/data/composite/things/artwork/withDate.js
new file mode 100644
index 00000000..5e05b814
--- /dev/null
+++ b/src/data/composite/things/artwork/withDate.js
@@ -0,0 +1,41 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+
+export default templateCompositeFrom({
+  annotation: `withDate`,
+
+  inputs: {
+    from: input({
+      defaultDependency: 'date',
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#date'],
+
+  steps: () => [
+    {
+      dependencies: [input('from')],
+      compute: (continuation, {
+        [input('from')]: date,
+      }) =>
+        (date
+          ? continuation.raiseOutput({'#date': date})
+          : continuation()),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: 'dateFromThingProperty',
+      output: input.value({'#date': null}),
+    }),
+
+    withPropertyFromObject({
+      object: 'thing',
+      property: 'dateFromThingProperty',
+    }).outputs({
+      ['#value']: '#date',
+    }),
+  ],
+})
diff --git a/src/data/composite/things/artwork/withPropertyFromAttachedArtwork.js b/src/data/composite/things/artwork/withPropertyFromAttachedArtwork.js
new file mode 100644
index 00000000..a2f954b9
--- /dev/null
+++ b/src/data/composite/things/artwork/withPropertyFromAttachedArtwork.js
@@ -0,0 +1,65 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {withResultOfAvailabilityCheck} from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+
+import withAttachedArtwork from './withAttachedArtwork.js';
+
+function getOutputName({
+  [input.staticValue('property')]: property,
+}) {
+  if (property) {
+    return `#attachedArtwork.${property}`;
+  } else {
+    return '#value';
+  }
+}
+
+export default templateCompositeFrom({
+  annotation: `withPropertyFromAttachedArtwork`,
+
+  inputs: {
+    property: input({type: 'string'}),
+  },
+
+  outputs: inputs => [getOutputName(inputs)],
+
+  steps: () => [
+    {
+      dependencies: [input.staticValue('property')],
+      compute: (continuation, inputs) =>
+        continuation({'#output': getOutputName(inputs)}),
+    },
+
+    withAttachedArtwork(),
+
+    withResultOfAvailabilityCheck({
+      from: '#attachedArtwork',
+    }),
+
+    {
+      dependencies: ['#availability', '#output'],
+      compute: (continuation, {
+        ['#availability']: availability,
+        ['#output']: output,
+      }) =>
+        (availability
+          ? continuation()
+          : continuation.raiseOutput({[output]: null})),
+    },
+
+    withPropertyFromObject({
+      object: '#attachedArtwork',
+      property: input('property'),
+    }),
+
+    {
+      dependencies: ['#value', '#output'],
+      compute: (continuation, {
+        ['#value']: value,
+        ['#output']: output,
+      }) =>
+        continuation.raiseOutput({[output]: value}),
+    },
+  ],
+});
diff --git a/src/data/composite/things/content/contentArtists.js b/src/data/composite/things/content/contentArtists.js
new file mode 100644
index 00000000..8d5db5a5
--- /dev/null
+++ b/src/data/composite/things/content/contentArtists.js
@@ -0,0 +1,40 @@
+import {input, templateCompositeFrom} from '#composite';
+import {validateReferenceList} from '#validators';
+
+import {exitWithoutDependency, exposeDependency}
+  from '#composite/control-flow';
+import {withResolvedReferenceList} from '#composite/wiki-data';
+import {soupyFind} from '#composite/wiki-properties';
+
+import withExpressedOrImplicitArtistReferences
+  from './helpers/withExpressedOrImplicitArtistReferences.js';
+
+export default templateCompositeFrom({
+  annotation: `contentArtists`,
+
+  compose: false,
+
+  update: {
+    validate: validateReferenceList('artist'),
+  },
+
+  steps: () => [
+    withExpressedOrImplicitArtistReferences({
+      from: input.updateValue(),
+    }),
+
+    exitWithoutDependency({
+      dependency: '#artistReferences',
+      value: input.value([]),
+    }),
+
+    withResolvedReferenceList({
+      list: '#artistReferences',
+      find: soupyFind.input('artist'),
+    }),
+
+    exposeDependency({
+      dependency: '#resolvedReferenceList',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/content/hasAnnotationPart.js b/src/data/composite/things/content/hasAnnotationPart.js
new file mode 100644
index 00000000..83d175e3
--- /dev/null
+++ b/src/data/composite/things/content/hasAnnotationPart.js
@@ -0,0 +1,25 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {exposeDependency} from '#composite/control-flow';
+
+import withHasAnnotationPart from './withHasAnnotationPart.js';
+
+export default templateCompositeFrom({
+  annotation: `hasAnnotationPart`,
+
+  compose: false,
+
+  inputs: {
+    part: input({type: 'string'}),
+  },
+
+  steps: () => [
+    withHasAnnotationPart({
+      part: input('part'),
+    }),
+
+    exposeDependency({
+      dependency: '#hasAnnotationPart',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/content/helpers/withExpressedOrImplicitArtistReferences.js b/src/data/composite/things/content/helpers/withExpressedOrImplicitArtistReferences.js
new file mode 100644
index 00000000..62799d43
--- /dev/null
+++ b/src/data/composite/things/content/helpers/withExpressedOrImplicitArtistReferences.js
@@ -0,0 +1,60 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withFilteredList, withMappedList} from '#composite/data';
+import {withContentNodes} from '#composite/wiki-data';
+
+export default templateCompositeFrom({
+  annotation: `withExpressedOrImplicitArtistReferences`,
+
+  inputs: {
+    from: input({type: 'array', acceptsNull: true}),
+  },
+
+  outputs: ['#artistReferences'],
+
+  steps: () => [
+    {
+      dependencies: [input('from')],
+      compute: (continuation, {
+        [input('from')]: expressedArtistReferences,
+      }) =>
+        (expressedArtistReferences
+          ? continuation.raiseOutput({'#artistReferences': expressedArtistReferences})
+          : continuation()),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: 'artistText',
+      output: input.value({'#artistReferences': null}),
+    }),
+
+    withContentNodes({
+      from: 'artistText',
+    }),
+
+    withMappedList({
+      list: '#contentNodes',
+      map: input.value(node =>
+        node.type === 'tag' &&
+        node.data.replacerKey?.data === 'artist'),
+    }).outputs({
+      '#mappedList': '#artistTagFilter',
+    }),
+
+    withFilteredList({
+      list: '#contentNodes',
+      filter: '#artistTagFilter',
+    }).outputs({
+      '#filteredList': '#artistTags',
+    }),
+
+    withMappedList({
+      list: '#artistTags',
+      map: input.value(node =>
+        node.data.replacerValue[0].data),
+    }).outputs({
+      '#mappedList': '#artistReferences',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/content/index.js b/src/data/composite/things/content/index.js
new file mode 100644
index 00000000..4176337d
--- /dev/null
+++ b/src/data/composite/things/content/index.js
@@ -0,0 +1,7 @@
+export {default as contentArtists} from './contentArtists.js';
+export {default as hasAnnotationPart} from './hasAnnotationPart.js';
+export {default as withAnnotationParts} from './withAnnotationParts.js';
+export {default as withHasAnnotationPart} from './withHasAnnotationPart.js';
+export {default as withSourceText} from './withSourceText.js';
+export {default as withSourceURLs} from './withSourceURLs.js';
+export {default as withWebArchiveDate} from './withWebArchiveDate.js';
diff --git a/src/data/composite/things/content/withAnnotationParts.js b/src/data/composite/things/content/withAnnotationParts.js
new file mode 100644
index 00000000..6311b57a
--- /dev/null
+++ b/src/data/composite/things/content/withAnnotationParts.js
@@ -0,0 +1,93 @@
+import {input, templateCompositeFrom} from '#composite';
+import {transposeArrays} from '#sugar';
+import {is} from '#validators';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withPropertyFromList} from '#composite/data';
+import {splitContentNodesAround, withContentNodes} from '#composite/wiki-data';
+
+export default templateCompositeFrom({
+  annotation: `withAnnotationParts`,
+
+  inputs: {
+    mode: input({
+      validate: is('strings', 'nodes'),
+    }),
+  },
+
+  outputs: ['#annotationParts'],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: 'annotation',
+      output: input.value({'#annotationParts': []}),
+    }),
+
+    withContentNodes({
+      from: 'annotation',
+    }),
+
+    splitContentNodesAround({
+      nodes: '#contentNodes',
+      around: input.value(/, */g),
+    }),
+
+    {
+      dependencies: ['#contentNodeLists', input('mode')],
+      compute: (continuation, {
+        ['#contentNodeLists']: nodeLists,
+        [input('mode')]: mode,
+      }) =>
+        (mode === 'nodes'
+          ? continuation.raiseOutput({'#annotationParts': nodeLists})
+          : continuation()),
+    },
+
+    {
+      dependencies: ['#contentNodeLists'],
+
+      compute: (continuation, {
+        ['#contentNodeLists']: nodeLists,
+      }) => continuation({
+        ['#firstNodes']:
+          nodeLists.map(list => list.at(0)),
+
+        ['#lastNodes']:
+          nodeLists.map(list => list.at(-1)),
+      }),
+    },
+
+    withPropertyFromList({
+      list: '#firstNodes',
+      property: input.value('i'),
+    }).outputs({
+      '#firstNodes.i': '#startIndices',
+    }),
+
+    withPropertyFromList({
+      list: '#lastNodes',
+      property: input.value('iEnd'),
+    }).outputs({
+      '#lastNodes.iEnd': '#endIndices',
+    }),
+
+    {
+      dependencies: [
+        'annotation',
+        '#startIndices',
+        '#endIndices',
+      ],
+
+      compute: (continuation, {
+        ['annotation']: annotation,
+        ['#startIndices']: startIndices,
+        ['#endIndices']: endIndices,
+      }) => continuation({
+        ['#annotationParts']:
+          transposeArrays([startIndices, endIndices])
+            .map(([start, end]) =>
+              annotation.slice(start, end)),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/content/withHasAnnotationPart.js b/src/data/composite/things/content/withHasAnnotationPart.js
new file mode 100644
index 00000000..4af554f3
--- /dev/null
+++ b/src/data/composite/things/content/withHasAnnotationPart.js
@@ -0,0 +1,43 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+import withAnnotationParts from './withAnnotationParts.js';
+
+export default templateCompositeFrom({
+  annotation: `withHasAnnotationPart`,
+
+  inputs: {
+    part: input({type: 'string'}),
+  },
+
+  outputs: ['#hasAnnotationPart'],
+
+  steps: () => [
+    withAnnotationParts({
+      mode: input.value('strings'),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#annotationParts',
+      output: input.value({'#hasAnnotationPart': false}),
+    }),
+
+    {
+      dependencies: [
+        input('part'),
+        '#annotationParts',
+      ],
+
+      compute: (continuation, {
+        [input('part')]: search,
+        ['#annotationParts']: parts,
+      }) => continuation({
+        ['#hasAnnotationPart']:
+          parts.some(part =>
+            part.toLowerCase() ===
+            search.toLowerCase()),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/content/withSourceText.js b/src/data/composite/things/content/withSourceText.js
new file mode 100644
index 00000000..292306b7
--- /dev/null
+++ b/src/data/composite/things/content/withSourceText.js
@@ -0,0 +1,53 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+import withAnnotationParts from './withAnnotationParts.js';
+
+export default templateCompositeFrom({
+  annotation: `withSourceText`,
+
+  outputs: ['#sourceText'],
+
+  steps: () => [
+    withAnnotationParts({
+      mode: input.value('nodes'),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#annotationParts',
+      output: input.value({'#sourceText': null}),
+    }),
+
+    {
+      dependencies: ['#annotationParts'],
+      compute: (continuation, {
+        ['#annotationParts']: annotationParts,
+      }) => continuation({
+        ['#firstPartWithExternalLink']:
+          annotationParts
+            .find(nodes => nodes
+              .some(node => node.type === 'external-link')) ??
+          null,
+      }),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: '#firstPartWithExternalLink',
+      output: input.value({'#sourceText': null}),
+    }),
+
+    {
+      dependencies: ['annotation', '#firstPartWithExternalLink'],
+      compute: (continuation, {
+        ['annotation']: annotation,
+        ['#firstPartWithExternalLink']: nodes,
+      }) => continuation({
+        ['#sourceText']:
+          annotation.slice(
+            nodes.at(0).i,
+            nodes.at(-1).iEnd),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/content/withSourceURLs.js b/src/data/composite/things/content/withSourceURLs.js
new file mode 100644
index 00000000..f85ff9ea
--- /dev/null
+++ b/src/data/composite/things/content/withSourceURLs.js
@@ -0,0 +1,62 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withFilteredList, withMappedList} from '#composite/data';
+
+import withAnnotationParts from './withAnnotationParts.js';
+
+export default templateCompositeFrom({
+  annotation: `withSourceURLs`,
+
+  outputs: ['#sourceURLs'],
+
+  steps: () => [
+    withAnnotationParts({
+      mode: input.value('nodes'),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#annotationParts',
+      output: input.value({'#sourceURLs': []}),
+    }),
+
+    {
+      dependencies: ['#annotationParts'],
+      compute: (continuation, {
+        ['#annotationParts']: annotationParts,
+      }) => continuation({
+        ['#firstPartWithExternalLink']:
+          annotationParts
+            .find(nodes => nodes
+              .some(node => node.type === 'external-link')) ??
+          null,
+      }),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: '#firstPartWithExternalLink',
+      output: input.value({'#sourceURLs': []}),
+    }),
+
+    withMappedList({
+      list: '#firstPartWithExternalLink',
+      map: input.value(node => node.type === 'external-link'),
+    }).outputs({
+      '#mappedList': '#externalLinkFilter',
+    }),
+
+    withFilteredList({
+      list: '#firstPartWithExternalLink',
+      filter: '#externalLinkFilter',
+    }).outputs({
+      '#filteredList': '#externalLinks',
+    }),
+
+    withMappedList({
+      list: '#externalLinks',
+      map: input.value(node => node.data.href),
+    }).outputs({
+      '#mappedList': '#sourceURLs',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/content/withWebArchiveDate.js b/src/data/composite/things/content/withWebArchiveDate.js
new file mode 100644
index 00000000..3aaa4f64
--- /dev/null
+++ b/src/data/composite/things/content/withWebArchiveDate.js
@@ -0,0 +1,41 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+export default templateCompositeFrom({
+  annotation: `withWebArchiveDate`,
+
+  outputs: ['#webArchiveDate'],
+
+  steps: () => [
+    {
+      dependencies: ['annotation'],
+
+      compute: (continuation, {annotation}) =>
+        continuation({
+          ['#dateText']:
+            annotation
+              ?.match(/https?:\/\/web.archive.org\/web\/([0-9]{8,8})[0-9]*\//)
+              ?.[1] ??
+            null,
+        }),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: '#dateText',
+      output: input.value({['#webArchiveDate']: null}),
+    }),
+
+    {
+      dependencies: ['#dateText'],
+      compute: (continuation, {['#dateText']: dateText}) =>
+        continuation({
+          ['#webArchiveDate']:
+            new Date(
+              dateText.slice(0, 4) + '/' +
+              dateText.slice(4, 6) + '/' +
+              dateText.slice(6, 8)),
+        }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/contribution/index.js b/src/data/composite/things/contribution/index.js
new file mode 100644
index 00000000..9b22be2e
--- /dev/null
+++ b/src/data/composite/things/contribution/index.js
@@ -0,0 +1,7 @@
+export {default as inheritFromContributionPresets} from './inheritFromContributionPresets.js';
+export {default as thingPropertyMatches} from './thingPropertyMatches.js';
+export {default as thingReferenceTypeMatches} from './thingReferenceTypeMatches.js';
+export {default as withContainingReverseContributionList} from './withContainingReverseContributionList.js';
+export {default as withContributionArtist} from './withContributionArtist.js';
+export {default as withContributionContext} from './withContributionContext.js';
+export {default as withMatchingContributionPresets} from './withMatchingContributionPresets.js';
diff --git a/src/data/composite/things/contribution/inheritFromContributionPresets.js b/src/data/composite/things/contribution/inheritFromContributionPresets.js
new file mode 100644
index 00000000..a74e6db3
--- /dev/null
+++ b/src/data/composite/things/contribution/inheritFromContributionPresets.js
@@ -0,0 +1,61 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withPropertyFromList} from '#composite/data';
+
+import withMatchingContributionPresets
+  from './withMatchingContributionPresets.js';
+
+export default templateCompositeFrom({
+  annotation: `inheritFromContributionPresets`,
+
+  inputs: {
+    property: input({type: 'string'}),
+  },
+
+  steps: () => [
+    withMatchingContributionPresets().outputs({
+      '#matchingContributionPresets': '#presets',
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#presets',
+      mode: input.value('empty'),
+    }),
+
+    withPropertyFromList({
+      list: '#presets',
+      property: input('property'),
+    }),
+
+    {
+      dependencies: ['#values'],
+
+      compute: (continuation, {
+        ['#values']: values,
+      }) => continuation({
+        ['#index']:
+          values.findIndex(value =>
+            value !== undefined &&
+            value !== null),
+      }),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: '#index',
+      mode: input.value('index'),
+    }),
+
+    {
+      dependencies: ['#values', '#index'],
+
+      compute: (continuation, {
+        ['#values']: values,
+        ['#index']: index,
+      }) => continuation({
+        ['#value']:
+          values[index],
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/contribution/thingPropertyMatches.js b/src/data/composite/things/contribution/thingPropertyMatches.js
new file mode 100644
index 00000000..a678c3f5
--- /dev/null
+++ b/src/data/composite/things/contribution/thingPropertyMatches.js
@@ -0,0 +1,45 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {exitWithoutDependency} from '#composite/control-flow';
+
+export default templateCompositeFrom({
+  annotation: `thingPropertyMatches`,
+
+  compose: false,
+
+  inputs: {
+    value: input({type: 'string'}),
+  },
+
+  steps: () => [
+    {
+      dependencies: ['thing', 'thingProperty'],
+
+      compute: (continuation, {thing, thingProperty}) =>
+        continuation({
+          ['#thingProperty']:
+            (thing.constructor[Symbol.for('Thing.referenceType')] === 'artwork'
+              ? thing.artistContribsFromThingProperty
+              : thingProperty),
+        }),
+    },
+
+    exitWithoutDependency({
+      dependency: '#thingProperty',
+      value: input.value(false),
+    }),
+
+    {
+      dependencies: [
+        '#thingProperty',
+        input('value'),
+      ],
+
+      compute: ({
+        ['#thingProperty']: thingProperty,
+        [input('value')]: value,
+      }) =>
+        thingProperty === value,
+    },
+  ],
+});
diff --git a/src/data/composite/things/contribution/thingReferenceTypeMatches.js b/src/data/composite/things/contribution/thingReferenceTypeMatches.js
new file mode 100644
index 00000000..4042e78f
--- /dev/null
+++ b/src/data/composite/things/contribution/thingReferenceTypeMatches.js
@@ -0,0 +1,66 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {exitWithoutDependency} from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+
+export default templateCompositeFrom({
+  annotation: `thingReferenceTypeMatches`,
+
+  compose: false,
+
+  inputs: {
+    value: input({type: 'string'}),
+  },
+
+  steps: () => [
+    exitWithoutDependency({
+      dependency: 'thing',
+      value: input.value(false),
+    }),
+
+    withPropertyFromObject({
+      object: 'thing',
+      property: input.value('constructor'),
+    }),
+
+    {
+      dependencies: [
+        '#thing.constructor',
+        input('value'),
+      ],
+
+      compute: (continuation, {
+        ['#thing.constructor']: constructor,
+        [input('value')]: value,
+      }) =>
+        (constructor[Symbol.for('Thing.referenceType')] === value
+          ? continuation.exit(true)
+       : constructor[Symbol.for('Thing.referenceType')] === 'artwork'
+          ? continuation()
+          : continuation.exit(false)),
+    },
+
+    withPropertyFromObject({
+      object: 'thing',
+      property: input.value('thing'),
+    }),
+
+    withPropertyFromObject({
+      object: '#thing.thing',
+      property: input.value('constructor'),
+    }),
+
+    {
+      dependencies: [
+        '#thing.thing.constructor',
+        input('value'),
+      ],
+
+      compute: ({
+        ['#thing.thing.constructor']: constructor,
+        [input('value')]: value,
+      }) =>
+        constructor[Symbol.for('Thing.referenceType')] === value,
+    },
+  ],
+});
diff --git a/src/data/composite/things/contribution/withContainingReverseContributionList.js b/src/data/composite/things/contribution/withContainingReverseContributionList.js
new file mode 100644
index 00000000..175d6cbb
--- /dev/null
+++ b/src/data/composite/things/contribution/withContainingReverseContributionList.js
@@ -0,0 +1,80 @@
+// Get the artist's contribution list containing this property. Although that
+// list literally includes both dated and dateless contributions, here, if the
+// current contribution is dateless, the list is filtered to only include
+// dateless contributions from the same immediately nearby context.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency, withResultOfAvailabilityCheck}
+  from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+
+import withContributionArtist from './withContributionArtist.js';
+
+export default templateCompositeFrom({
+  annotation: `withContainingReverseContributionList`,
+
+  inputs: {
+    artistProperty: input({
+      defaultDependency: 'artistProperty',
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#containingReverseContributionList'],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: input('artistProperty'),
+      output: input.value({
+        ['#containingReverseContributionList']:
+          null,
+      }),
+    }),
+
+    withContributionArtist(),
+
+    withPropertyFromObject({
+      object: '#artist',
+      property: input('artistProperty'),
+    }).outputs({
+      ['#value']: '#list',
+    }),
+
+    withResultOfAvailabilityCheck({
+      from: 'date',
+    }).outputs({
+      ['#availability']: '#hasDate',
+    }),
+
+    {
+      dependencies: ['#hasDate', '#list'],
+      compute: (continuation, {
+        ['#hasDate']: hasDate,
+        ['#list']: list,
+      }) =>
+        (hasDate
+          ? continuation.raiseOutput({
+              ['#containingReverseContributionList']:
+                list.filter(contrib => contrib.date),
+            })
+          : continuation({
+              ['#list']:
+                list.filter(contrib => !contrib.date),
+            })),
+    },
+
+    {
+      dependencies: ['#list', 'thing'],
+      compute: (continuation, {
+        ['#list']: list,
+        ['thing']: thing,
+      }) => continuation({
+        ['#containingReverseContributionList']:
+          (thing.album
+            ? list.filter(contrib => contrib.thing.album === thing.album)
+            : list),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/contribution/withContributionArtist.js b/src/data/composite/things/contribution/withContributionArtist.js
new file mode 100644
index 00000000..5f81c716
--- /dev/null
+++ b/src/data/composite/things/contribution/withContributionArtist.js
@@ -0,0 +1,26 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {withResolvedReference} from '#composite/wiki-data';
+import {soupyFind} from '#composite/wiki-properties';
+
+export default templateCompositeFrom({
+  annotation: `withContributionArtist`,
+
+  inputs: {
+    ref: input({
+      type: 'string',
+      defaultDependency: 'artist',
+    }),
+  },
+
+  outputs: ['#artist'],
+
+  steps: () => [
+    withResolvedReference({
+      ref: input('ref'),
+      find: soupyFind.input('artist'),
+    }).outputs({
+      '#resolvedReference': '#artist',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/contribution/withContributionContext.js b/src/data/composite/things/contribution/withContributionContext.js
new file mode 100644
index 00000000..3c1c31c0
--- /dev/null
+++ b/src/data/composite/things/contribution/withContributionContext.js
@@ -0,0 +1,45 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+export default templateCompositeFrom({
+  annotation: `withContributionContext`,
+
+  outputs: [
+    '#contributionTarget',
+    '#contributionProperty',
+  ],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: 'thing',
+      output: input.value({
+        '#contributionTarget': null,
+        '#contributionProperty': null,
+      }),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: 'thingProperty',
+      output: input.value({
+        '#contributionTarget': null,
+        '#contributionProperty': null,
+      }),
+    }),
+
+    {
+      dependencies: ['thing', 'thingProperty'],
+
+      compute: (continuation, {
+        ['thing']: thing,
+        ['thingProperty']: thingProperty,
+      }) => continuation({
+        ['#contributionTarget']:
+          thing.constructor[Symbol.for('Thing.referenceType')],
+
+        ['#contributionProperty']:
+          thingProperty,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/contribution/withMatchingContributionPresets.js b/src/data/composite/things/contribution/withMatchingContributionPresets.js
new file mode 100644
index 00000000..09454164
--- /dev/null
+++ b/src/data/composite/things/contribution/withMatchingContributionPresets.js
@@ -0,0 +1,70 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+
+import withContributionContext from './withContributionContext.js';
+
+export default templateCompositeFrom({
+  annotation: `withMatchingContributionPresets`,
+
+  outputs: ['#matchingContributionPresets'],
+
+  steps: () => [
+    withPropertyFromObject({
+      object: 'thing',
+      property: input.value('wikiInfo'),
+      internal: input.value(true),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#thing.wikiInfo',
+      output: input.value({
+        '#matchingContributionPresets': null,
+      }),
+    }),
+
+    withPropertyFromObject({
+      object: '#thing.wikiInfo',
+      property: input.value('contributionPresets'),
+    }).outputs({
+      '#thing.wikiInfo.contributionPresets': '#contributionPresets',
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#contributionPresets',
+      mode: input.value('empty'),
+      output: input.value({
+        '#matchingContributionPresets': [],
+      }),
+    }),
+
+    withContributionContext(),
+
+    {
+      dependencies: [
+        '#contributionPresets',
+        '#contributionTarget',
+        '#contributionProperty',
+        'annotation',
+      ],
+
+      compute: (continuation, {
+        ['#contributionPresets']: presets,
+        ['#contributionTarget']: target,
+        ['#contributionProperty']: property,
+        ['annotation']: annotation,
+      }) => continuation({
+        ['#matchingContributionPresets']:
+          presets
+            .filter(preset =>
+              preset.context[0] === target &&
+              preset.context.slice(1).includes(property) &&
+              // For now, only match if the annotation is a complete match.
+              // Partial matches (e.g. because the contribution includes "two"
+              // annotations, separated by commas) don't count.
+              preset.annotation === annotation),
+      })
+    },
+  ],
+});
diff --git a/src/data/composite/things/flash-act/index.js b/src/data/composite/things/flash-act/index.js
new file mode 100644
index 00000000..40fecd2f
--- /dev/null
+++ b/src/data/composite/things/flash-act/index.js
@@ -0,0 +1 @@
+export {default as withFlashSide} from './withFlashSide.js';
diff --git a/src/data/composite/things/flash-act/withFlashSide.js b/src/data/composite/things/flash-act/withFlashSide.js
new file mode 100644
index 00000000..e09f06e6
--- /dev/null
+++ b/src/data/composite/things/flash-act/withFlashSide.js
@@ -0,0 +1,22 @@
+// Gets the flash act's side. This will early exit if flashSideData is missing.
+// If there's no side whose list of flash acts includes this act, the output
+// dependency will be null.
+
+import {templateCompositeFrom} from '#composite';
+
+import {withUniqueReferencingThing} from '#composite/wiki-data';
+import {soupyReverse} from '#composite/wiki-properties';
+
+export default templateCompositeFrom({
+  annotation: `withFlashSide`,
+
+  outputs: ['#flashSide'],
+
+  steps: () => [
+    withUniqueReferencingThing({
+      reverse: soupyReverse.input('flashSidesWhoseActsInclude'),
+    }).outputs({
+      ['#uniqueReferencingThing']: '#flashSide',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/flash/withFlashAct.js b/src/data/composite/things/flash/withFlashAct.js
index ada2dcfe..87922aff 100644
--- a/src/data/composite/things/flash/withFlashAct.js
+++ b/src/data/composite/things/flash/withFlashAct.js
@@ -1,108 +1,22 @@
 // Gets the flash's act. This will early exit if flashActData is missing.
-// By default, if there's no flash whose list of flashes includes this flash,
-// the output dependency will be null; set {notFoundMode: 'exit'} to early
-// exit instead.
-//
-// This step models with Flash.withAlbum.
+// If there's no flash whose list of flashes includes this flash, the output
+// dependency will be null.
 
-import {input, templateCompositeFrom} from '#composite';
-import {is} from '#validators';
+import {templateCompositeFrom} from '#composite';
 
-import {exitWithoutDependency, withResultOfAvailabilityCheck}
-  from '#composite/control-flow';
-import {withPropertyFromList} from '#composite/data';
+import {withUniqueReferencingThing} from '#composite/wiki-data';
+import {soupyReverse} from '#composite/wiki-properties';
 
 export default templateCompositeFrom({
   annotation: `withFlashAct`,
 
-  inputs: {
-    notFoundMode: input({
-      validate: is('exit', 'null'),
-      defaultValue: 'null',
-    }),
-  },
-
   outputs: ['#flashAct'],
 
   steps: () => [
-    // null flashActData is always an early exit.
-
-    exitWithoutDependency({
-      dependency: 'flashActData',
-      mode: input.value('null'),
-    }),
-
-    // empty flashActData conditionally exits early or outputs null.
-
-    withResultOfAvailabilityCheck({
-      from: 'flashActData',
-      mode: input.value('empty'),
-    }).outputs({
-      '#availability': '#flashActDataAvailability',
-    }),
-
-    {
-      dependencies: [input('notFoundMode'), '#flashActDataAvailability'],
-      compute(continuation, {
-        [input('notFoundMode')]: notFoundMode,
-        ['#flashActDataAvailability']: flashActDataIsAvailable,
-      }) {
-        if (flashActDataIsAvailable) return continuation();
-        switch (notFoundMode) {
-          case 'exit': return continuation.exit(null);
-          case 'null': return continuation.raiseOutput({'#flashAct': null});
-        }
-      },
-    },
-
-    withPropertyFromList({
-      list: 'flashActData',
-      property: input.value('flashes'),
-    }),
-
-    {
-      dependencies: [input.myself(), '#flashActData.flashes'],
-      compute: (continuation, {
-        [input.myself()]: track,
-        ['#flashActData.flashes']: flashLists,
-      }) => continuation({
-        ['#flashActIndex']:
-          flashLists.findIndex(flashes => flashes.includes(track)),
-      }),
-    },
-
-    // album not found conditionally exits or outputs null.
-
-    withResultOfAvailabilityCheck({
-      from: '#flashActIndex',
-      mode: input.value('index'),
+    withUniqueReferencingThing({
+      reverse: soupyReverse.input('flashActsWhoseFlashesInclude'),
     }).outputs({
-      '#availability': '#flashActAvailability',
+      ['#uniqueReferencingThing']: '#flashAct',
     }),
-
-    {
-      dependencies: [input('notFoundMode'), '#flashActAvailability'],
-      compute(continuation, {
-        [input('notFoundMode')]: notFoundMode,
-        ['#flashActAvailability']: flashActIsAvailable,
-      }) {
-        if (flashActIsAvailable) return continuation();
-        switch (notFoundMode) {
-          case 'exit': return continuation.exit(null);
-          case 'null': return continuation.raiseOutput({'#flashAct': null});
-        }
-      },
-    },
-
-    {
-      dependencies: ['flashActData', '#flashActIndex'],
-      compute: (continuation, {
-        ['flashActData']: flashActData,
-        ['#flashActIndex']: flashActIndex,
-      }) => continuation.raiseOutput({
-        ['#flashAct']:
-          flashActData[flashActIndex],
-      }),
-    },
   ],
 });
diff --git a/src/data/composite/things/track-section/index.js b/src/data/composite/things/track-section/index.js
new file mode 100644
index 00000000..f11a2ab5
--- /dev/null
+++ b/src/data/composite/things/track-section/index.js
@@ -0,0 +1,3 @@
+export {default as withAlbum} from './withAlbum.js';
+export {default as withContinueCountingFrom} from './withContinueCountingFrom.js';
+export {default as withStartCountingFrom} from './withStartCountingFrom.js';
diff --git a/src/data/composite/things/track-section/withAlbum.js b/src/data/composite/things/track-section/withAlbum.js
new file mode 100644
index 00000000..e257062e
--- /dev/null
+++ b/src/data/composite/things/track-section/withAlbum.js
@@ -0,0 +1,20 @@
+// Gets the track section's album.
+
+import {templateCompositeFrom} from '#composite';
+
+import {withUniqueReferencingThing} from '#composite/wiki-data';
+import {soupyReverse} from '#composite/wiki-properties';
+
+export default templateCompositeFrom({
+  annotation: `withAlbum`,
+
+  outputs: ['#album'],
+
+  steps: () => [
+    withUniqueReferencingThing({
+      reverse: soupyReverse.input('albumsWhoseTrackSectionsInclude'),
+    }).outputs({
+      ['#uniqueReferencingThing']: '#album',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/track-section/withContinueCountingFrom.js b/src/data/composite/things/track-section/withContinueCountingFrom.js
new file mode 100644
index 00000000..0ca52b6c
--- /dev/null
+++ b/src/data/composite/things/track-section/withContinueCountingFrom.js
@@ -0,0 +1,25 @@
+import {templateCompositeFrom} from '#composite';
+
+import withStartCountingFrom from './withStartCountingFrom.js';
+
+export default templateCompositeFrom({
+  annotation: `withContinueCountingFrom`,
+
+  outputs: ['#continueCountingFrom'],
+
+  steps: () => [
+    withStartCountingFrom(),
+
+    {
+      dependencies: ['#startCountingFrom', 'tracks'],
+      compute: (continuation, {
+        ['#startCountingFrom']: startCountingFrom,
+        ['tracks']: tracks,
+      }) => continuation({
+        ['#continueCountingFrom']:
+          startCountingFrom +
+          tracks.length,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/track-section/withStartCountingFrom.js b/src/data/composite/things/track-section/withStartCountingFrom.js
new file mode 100644
index 00000000..ef345327
--- /dev/null
+++ b/src/data/composite/things/track-section/withStartCountingFrom.js
@@ -0,0 +1,64 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withNearbyItemFromList, withPropertyFromObject} from '#composite/data';
+
+import withAlbum from './withAlbum.js';
+
+export default templateCompositeFrom({
+  annotation: `withStartCountingFrom`,
+
+  inputs: {
+    from: input({
+      type: 'number',
+      defaultDependency: 'startCountingFrom',
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#startCountingFrom'],
+
+  steps: () => [
+    {
+      dependencies: [input('from')],
+      compute: (continuation, {
+        [input('from')]: from,
+      }) =>
+        (from === null
+          ? continuation()
+          : continuation.raiseOutput({'#startCountingFrom': from})),
+    },
+
+    withAlbum(),
+
+    raiseOutputWithoutDependency({
+      dependency: '#album',
+      output: input.value({'#startCountingFrom': 1}),
+    }),
+
+    withPropertyFromObject({
+      object: '#album',
+      property: input.value('trackSections'),
+    }),
+
+    withNearbyItemFromList({
+      list: '#album.trackSections',
+      item: input.myself(),
+      offset: input.value(-1),
+    }).outputs({
+      '#nearbyItem': '#previousTrackSection',
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#previousTrackSection',
+      output: input.value({'#startCountingFrom': 1}),
+    }),
+
+    withPropertyFromObject({
+      object: '#previousTrackSection',
+      property: input.value('continueCountingFrom'),
+    }).outputs({
+      '#previousTrackSection.continueCountingFrom': '#startCountingFrom',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/track/index.js b/src/data/composite/things/track/index.js
index cc723a24..e789e736 100644
--- a/src/data/composite/things/track/index.js
+++ b/src/data/composite/things/track/index.js
@@ -1,11 +1,17 @@
 export {default as exitWithoutUniqueCoverArt} from './exitWithoutUniqueCoverArt.js';
-export {default as inferredAdditionalNameList} from './inferredAdditionalNameList.js';
-export {default as inheritFromOriginalRelease} from './inheritFromOriginalRelease.js';
-export {default as sharedAdditionalNameList} from './sharedAdditionalNameList.js';
-export {default as trackReverseReferenceList} from './trackReverseReferenceList.js';
-export {default as withAlbum} from './withAlbum.js';
+export {default as inheritContributionListFromMainRelease} from './inheritContributionListFromMainRelease.js';
+export {default as inheritFromMainRelease} from './inheritFromMainRelease.js';
+export {default as withAllReleases} from './withAllReleases.js';
 export {default as withAlwaysReferenceByDirectory} from './withAlwaysReferenceByDirectory.js';
 export {default as withContainingTrackSection} from './withContainingTrackSection.js';
+export {default as withCoverArtistContribs} from './withCoverArtistContribs.js';
+export {default as withDate} from './withDate.js';
+export {default as withDirectorySuffix} from './withDirectorySuffix.js';
 export {default as withHasUniqueCoverArt} from './withHasUniqueCoverArt.js';
+export {default as withMainRelease} from './withMainRelease.js';
 export {default as withOtherReleases} from './withOtherReleases.js';
 export {default as withPropertyFromAlbum} from './withPropertyFromAlbum.js';
+export {default as withPropertyFromMainRelease} from './withPropertyFromMainRelease.js';
+export {default as withSuffixDirectoryFromAlbum} from './withSuffixDirectoryFromAlbum.js';
+export {default as withTrackArtDate} from './withTrackArtDate.js';
+export {default as withTrackNumber} from './withTrackNumber.js';
diff --git a/src/data/composite/things/track/inferredAdditionalNameList.js b/src/data/composite/things/track/inferredAdditionalNameList.js
deleted file mode 100644
index 58e8d2a1..00000000
--- a/src/data/composite/things/track/inferredAdditionalNameList.js
+++ /dev/null
@@ -1,67 +0,0 @@
-// Infers additional name entries from other releases that were titled
-// differently; the corresponding releases are stored in eacn entry's "from"
-// array, which will include multiple items, if more than one other release
-// shares the same name differing from this one's.
-
-import {input, templateCompositeFrom} from '#composite';
-import {chunkByProperties} from '#sugar';
-
-import {exitWithoutDependency} from '#composite/control-flow';
-import {withFilteredList, withPropertyFromList} from '#composite/data';
-import {withThingsSortedAlphabetically} from '#composite/wiki-data';
-
-import withOtherReleases from './withOtherReleases.js';
-
-export default templateCompositeFrom({
-  annotation: `inferredAdditionalNameList`,
-
-  compose: false,
-
-  steps: () => [
-    withOtherReleases(),
-
-    exitWithoutDependency({
-      dependency: '#otherReleases',
-      mode: input.value('empty'),
-      value: input.value([]),
-    }),
-
-    withPropertyFromList({
-      list: '#otherReleases',
-      property: input.value('name'),
-    }),
-
-    {
-      dependencies: ['#otherReleases.name', 'name'],
-      compute: (continuation, {
-        ['#otherReleases.name']: releaseNames,
-        ['name']: ownName,
-      }) => continuation({
-        ['#nameFilter']:
-          releaseNames.map(name => name !== ownName),
-      }),
-    },
-
-    withFilteredList({
-      list: '#otherReleases',
-      filter: '#nameFilter',
-    }).outputs({
-      '#filteredList': '#differentlyNamedReleases',
-    }),
-
-    withThingsSortedAlphabetically({
-      things: '#differentlyNamedReleases',
-    }).outputs({
-      '#sortedThings': '#differentlyNamedReleases',
-    }),
-
-    {
-      dependencies: ['#differentlyNamedReleases'],
-      compute: ({
-        ['#differentlyNamedReleases']: releases,
-      }) =>
-        chunkByProperties(releases, ['name'])
-          .map(({name, chunk}) => ({name, from: chunk})),
-    },
-  ],
-});
diff --git a/src/data/composite/things/track/inheritContributionListFromMainRelease.js b/src/data/composite/things/track/inheritContributionListFromMainRelease.js
new file mode 100644
index 00000000..89252feb
--- /dev/null
+++ b/src/data/composite/things/track/inheritContributionListFromMainRelease.js
@@ -0,0 +1,44 @@
+// Like inheritFromMainRelease, but tuned for contributions.
+// Recontextualizes contributions for this track.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {exposeDependency, raiseOutputWithoutDependency}
+  from '#composite/control-flow';
+import {withRecontextualizedContributionList, withRedatedContributionList}
+  from '#composite/wiki-data';
+
+import withDate from './withDate.js';
+import withPropertyFromMainRelease
+  from './withPropertyFromMainRelease.js';
+
+export default templateCompositeFrom({
+  annotation: `inheritContributionListFromMainRelease`,
+
+  steps: () => [
+    withPropertyFromMainRelease({
+      property: input.thisProperty(),
+      notFoundValue: input.value([]),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#isSecondaryRelease',
+      mode: input.value('falsy'),
+    }),
+
+    withRecontextualizedContributionList({
+      list: '#mainReleaseValue',
+    }),
+
+    withDate(),
+
+    withRedatedContributionList({
+      list: '#mainReleaseValue',
+      date: '#date',
+    }),
+
+    exposeDependency({
+      dependency: '#mainReleaseValue',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/track/inheritFromMainRelease.js b/src/data/composite/things/track/inheritFromMainRelease.js
new file mode 100644
index 00000000..b1cbb65e
--- /dev/null
+++ b/src/data/composite/things/track/inheritFromMainRelease.js
@@ -0,0 +1,41 @@
+// Early exits with the value for the same property as specified on the
+// main release, if this track is a secondary release, and otherwise continues
+// without providing any further dependencies.
+//
+// Like withMainRelease, this will early exit (with notFoundValue) if the
+// main release is specified by reference and that reference doesn't
+// resolve to anything.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {exposeDependency, raiseOutputWithoutDependency}
+  from '#composite/control-flow';
+
+import withPropertyFromMainRelease
+  from './withPropertyFromMainRelease.js';
+
+export default templateCompositeFrom({
+  annotation: `inheritFromMainRelease`,
+
+  inputs: {
+    notFoundValue: input({
+      defaultValue: null,
+    }),
+  },
+
+  steps: () => [
+    withPropertyFromMainRelease({
+      property: input.thisProperty(),
+      notFoundValue: input('notFoundValue'),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#isSecondaryRelease',
+      mode: input.value('falsy'),
+    }),
+
+    exposeDependency({
+      dependency: '#mainReleaseValue',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/track/inheritFromOriginalRelease.js b/src/data/composite/things/track/inheritFromOriginalRelease.js
deleted file mode 100644
index 27ed1387..00000000
--- a/src/data/composite/things/track/inheritFromOriginalRelease.js
+++ /dev/null
@@ -1,50 +0,0 @@
-// Early exits with a value inherited from the original release, if
-// this track is a rerelease, and otherwise continues with no further
-// dependencies provided. If allowOverride is true, then the continuation
-// will also be called if the original release exposed the requested
-// property as null.
-//
-// Like withOriginalRelease, this will early exit (with notFoundValue) if the
-// original release is specified by reference and that reference doesn't
-// resolve to anything.
-
-import {input, templateCompositeFrom} from '#composite';
-
-import withOriginalRelease from './withOriginalRelease.js';
-
-export default templateCompositeFrom({
-  annotation: `inheritFromOriginalRelease`,
-
-  inputs: {
-    property: input({type: 'string'}),
-    allowOverride: input({type: 'boolean', defaultValue: false}),
-    notFoundValue: input({defaultValue: null}),
-  },
-
-  steps: () => [
-    withOriginalRelease({
-      notFoundValue: input('notFoundValue'),
-    }),
-
-    {
-      dependencies: [
-        '#originalRelease',
-        input('property'),
-        input('allowOverride'),
-      ],
-
-      compute: (continuation, {
-        ['#originalRelease']: originalRelease,
-        [input('property')]: originalProperty,
-        [input('allowOverride')]: allowOverride,
-      }) => {
-        if (!originalRelease) return continuation();
-
-        const value = originalRelease[originalProperty];
-        if (allowOverride && value === null) return continuation();
-
-        return continuation.exit(value);
-      },
-    },
-  ],
-});
diff --git a/src/data/composite/things/track/sharedAdditionalNameList.js b/src/data/composite/things/track/sharedAdditionalNameList.js
deleted file mode 100644
index 1806ec80..00000000
--- a/src/data/composite/things/track/sharedAdditionalNameList.js
+++ /dev/null
@@ -1,38 +0,0 @@
-// Compiles additional names directly provided by other releases.
-
-import {input, templateCompositeFrom} from '#composite';
-
-import {exitWithoutDependency, exposeDependency}
-  from '#composite/control-flow';
-import {withFlattenedList, withPropertyFromList} from '#composite/data';
-
-import withOtherReleases from './withOtherReleases.js';
-
-export default templateCompositeFrom({
-  annotation: `sharedAdditionalNameList`,
-
-  compose: false,
-
-  steps: () => [
-    withOtherReleases(),
-
-    exitWithoutDependency({
-      dependency: '#otherReleases',
-      mode: input.value('empty'),
-      value: input.value([]),
-    }),
-
-    withPropertyFromList({
-      list: '#otherReleases',
-      property: input.value('additionalNames'),
-    }),
-
-    withFlattenedList({
-      list: '#otherReleases.additionalNames',
-    }),
-
-    exposeDependency({
-      dependency: '#flattenedList',
-    }),
-  ],
-});
diff --git a/src/data/composite/things/track/trackAdditionalNameList.js b/src/data/composite/things/track/trackAdditionalNameList.js
deleted file mode 100644
index 65a2263d..00000000
--- a/src/data/composite/things/track/trackAdditionalNameList.js
+++ /dev/null
@@ -1,38 +0,0 @@
-// Compiles additional names from various sources.
-
-import {input, templateCompositeFrom} from '#composite';
-import {isAdditionalNameList} from '#validators';
-
-import withInferredAdditionalNames from './withInferredAdditionalNames.js';
-import withSharedAdditionalNames from './withSharedAdditionalNames.js';
-
-export default templateCompositeFrom({
-  annotation: `trackAdditionalNameList`,
-
-  compose: false,
-
-  update: {validate: isAdditionalNameList},
-
-  steps: () => [
-    withInferredAdditionalNames(),
-    withSharedAdditionalNames(),
-
-    {
-      dependencies: [
-        '#inferredAdditionalNames',
-        '#sharedAdditionalNames',
-        input.updateValue(),
-      ],
-
-      compute: ({
-        ['#inferredAdditionalNames']: inferredAdditionalNames,
-        ['#sharedAdditionalNames']: sharedAdditionalNames,
-        [input.updateValue()]: providedAdditionalNames,
-      }) => [
-        ...providedAdditionalNames ?? [],
-        ...sharedAdditionalNames,
-        ...inferredAdditionalNames,
-      ],
-    },
-  ],
-});
diff --git a/src/data/composite/things/track/trackReverseReferenceList.js b/src/data/composite/things/track/trackReverseReferenceList.js
deleted file mode 100644
index 44940ae7..00000000
--- a/src/data/composite/things/track/trackReverseReferenceList.js
+++ /dev/null
@@ -1,38 +0,0 @@
-// Like a normal reverse reference list ("objects which reference this object
-// under a specified property"), only excluding rereleases from the possible
-// outputs. While it's useful to travel from a rerelease to the tracks it
-// references, rereleases aren't generally relevant from the perspective of
-// the tracks *being* referenced. Apart from hiding rereleases from lists on
-// the site, it also excludes keeps them from relational data processing, such
-// as on the "Tracks - by Times Referenced" listing page.
-
-import {input, templateCompositeFrom} from '#composite';
-import {withReverseReferenceList} from '#composite/wiki-data';
-
-export default templateCompositeFrom({
-  annotation: `trackReverseReferenceList`,
-
-  compose: false,
-
-  inputs: {
-    list: input({type: 'string'}),
-  },
-
-  steps: () => [
-    withReverseReferenceList({
-      data: 'trackData',
-      list: input('list'),
-    }),
-
-    {
-      flags: {expose: true},
-      expose: {
-        dependencies: ['#reverseReferenceList'],
-        compute: ({
-          ['#reverseReferenceList']: reverseReferenceList,
-        }) =>
-          reverseReferenceList.filter(track => !track.originalReleaseTrack),
-      },
-    },
-  ],
-});
diff --git a/src/data/composite/things/track/withAlbum.js b/src/data/composite/things/track/withAlbum.js
deleted file mode 100644
index cbd16dcd..00000000
--- a/src/data/composite/things/track/withAlbum.js
+++ /dev/null
@@ -1,108 +0,0 @@
-// Gets the track's album. This will early exit if albumData is missing.
-// By default, if there's no album whose list of tracks includes this track,
-// the output dependency will be null; set {notFoundMode: 'exit'} to early
-// exit instead.
-//
-// This step models with Flash.withFlashAct.
-
-import {input, templateCompositeFrom} from '#composite';
-import {is} from '#validators';
-
-import {exitWithoutDependency, withResultOfAvailabilityCheck}
-  from '#composite/control-flow';
-import {withPropertyFromList} from '#composite/data';
-
-export default templateCompositeFrom({
-  annotation: `withAlbum`,
-
-  inputs: {
-    notFoundMode: input({
-      validate: is('exit', 'null'),
-      defaultValue: 'null',
-    }),
-  },
-
-  outputs: ['#album'],
-
-  steps: () => [
-    // null albumData is always an early exit.
-
-    exitWithoutDependency({
-      dependency: 'albumData',
-      mode: input.value('null'),
-    }),
-
-    // empty albumData conditionally exits early or outputs null.
-
-    withResultOfAvailabilityCheck({
-      from: 'albumData',
-      mode: input.value('empty'),
-    }).outputs({
-      '#availability': '#albumDataAvailability',
-    }),
-
-    {
-      dependencies: [input('notFoundMode'), '#albumDataAvailability'],
-      compute(continuation, {
-        [input('notFoundMode')]: notFoundMode,
-        ['#albumDataAvailability']: albumDataIsAvailable,
-      }) {
-        if (albumDataIsAvailable) return continuation();
-        switch (notFoundMode) {
-          case 'exit': return continuation.exit(null);
-          case 'null': return continuation.raiseOutput({'#album': null});
-        }
-      },
-    },
-
-    withPropertyFromList({
-      list: 'albumData',
-      property: input.value('tracks'),
-    }),
-
-    {
-      dependencies: [input.myself(), '#albumData.tracks'],
-      compute: (continuation, {
-        [input.myself()]: track,
-        ['#albumData.tracks']: trackLists,
-      }) => continuation({
-        ['#albumIndex']:
-          trackLists.findIndex(tracks => tracks.includes(track)),
-      }),
-    },
-
-    // album not found conditionally exits or outputs null.
-
-    withResultOfAvailabilityCheck({
-      from: '#albumIndex',
-      mode: input.value('index'),
-    }).outputs({
-      '#availability': '#albumAvailability',
-    }),
-
-    {
-      dependencies: [input('notFoundMode'), '#albumAvailability'],
-      compute(continuation, {
-        [input('notFoundMode')]: notFoundMode,
-        ['#albumAvailability']: albumIsAvailable,
-      }) {
-        if (albumIsAvailable) return continuation();
-        switch (notFoundMode) {
-          case 'exit': return continuation.exit(null);
-          case 'null': return continuation.raiseOutput({'#album': null});
-        }
-      },
-    },
-
-    {
-      dependencies: ['albumData', '#albumIndex'],
-      compute: (continuation, {
-        ['albumData']: albumData,
-        ['#albumIndex']: albumIndex,
-      }) => continuation.raiseOutput({
-        ['#album']:
-          albumData[albumIndex],
-      }),
-    },
-  ],
-});
diff --git a/src/data/composite/things/track/withAllReleases.js b/src/data/composite/things/track/withAllReleases.js
new file mode 100644
index 00000000..891db102
--- /dev/null
+++ b/src/data/composite/things/track/withAllReleases.js
@@ -0,0 +1,46 @@
+// Gets all releases of the current track. All items of the outputs are
+// distinct Track objects; one track is the main release; all else are
+// secondary releases of that main release; and one item, which may be
+// the main release or one of the secondary releases, is the current
+// track. The results are sorted by date, and it is possible that the
+// main release is not actually the earliest/first.
+
+import {input, templateCompositeFrom} from '#composite';
+import {sortByDate} from '#sort';
+
+import {withPropertyFromObject} from '#composite/data';
+
+import withMainRelease from './withMainRelease.js';
+
+export default templateCompositeFrom({
+  annotation: `withAllReleases`,
+
+  outputs: ['#allReleases'],
+
+  steps: () => [
+    withMainRelease({
+      selfIfMain: input.value(true),
+      notFoundValue: input.value([]),
+    }),
+
+    // We don't talk about bruno no no
+    // Yes, this can perform a normal access equivalent to
+    // `this.secondaryReleases` from within a data composition.
+    // Oooooooooooooooooooooooooooooooooooooooooooooooo
+    withPropertyFromObject({
+      object: '#mainRelease',
+      property: input.value('secondaryReleases'),
+    }),
+
+    {
+      dependencies: ['#mainRelease', '#mainRelease.secondaryReleases'],
+      compute: (continuation, {
+        ['#mainRelease']: mainRelease,
+        ['#mainRelease.secondaryReleases']: secondaryReleases,
+      }) => continuation({
+        ['#allReleases']:
+          sortByDate([mainRelease, ...secondaryReleases]),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/track/withAlwaysReferenceByDirectory.js b/src/data/composite/things/track/withAlwaysReferenceByDirectory.js
index fac8e213..87edf21e 100644
--- a/src/data/composite/things/track/withAlwaysReferenceByDirectory.js
+++ b/src/data/composite/things/track/withAlwaysReferenceByDirectory.js
@@ -7,11 +7,17 @@ import {input, templateCompositeFrom} from '#composite';
 import find from '#find';
 import {isBoolean} from '#validators';
 
-import {exitWithoutDependency, exposeUpdateValueOrContinue}
-  from '#composite/control-flow';
 import {withPropertyFromObject} from '#composite/data';
 import {withResolvedReference} from '#composite/wiki-data';
 
+import {
+  exitWithoutDependency,
+  exposeDependencyOrContinue,
+  exposeUpdateValueOrContinue,
+} from '#composite/control-flow';
+
+import withPropertyFromAlbum from './withPropertyFromAlbum.js';
+
 export default templateCompositeFrom({
   annotation: `withAlwaysReferenceByDirectory`,
 
@@ -22,9 +28,20 @@ export default templateCompositeFrom({
       validate: input.value(isBoolean),
     }),
 
+    withPropertyFromAlbum({
+      property: input.value('alwaysReferenceTracksByDirectory'),
+    }),
+
+    // Falsy mode means this exposes true if the album's property is true,
+    // but continues if the property is false (which is also the default).
+    exposeDependencyOrContinue({
+      dependency: '#album.alwaysReferenceTracksByDirectory',
+      mode: input.value('falsy'),
+    }),
+
     // Remaining code is for defaulting to true if this track is a rerelease of
     // another with the same name, so everything further depends on access to
-    // trackData as well as originalReleaseTrack.
+    // trackData as well as mainReleaseTrack.
 
     exitWithoutDependency({
       dependency: 'trackData',
@@ -33,45 +50,46 @@ export default templateCompositeFrom({
     }),
 
     exitWithoutDependency({
-      dependency: 'originalReleaseTrack',
+      dependency: 'mainReleaseTrack',
       value: input.value(false),
     }),
 
-    // It's necessary to use the custom trackOriginalReleasesOnly find function
+    // It's necessary to use the custom trackMainReleasesOnly find function
     // here, so as to avoid recursion issues - the find.track() function depends
     // on accessing each track's alwaysReferenceByDirectory, which means it'll
     // hit *this track* - and thus this step - and end up recursing infinitely.
-    // By definition, find.trackOriginalReleasesOnly excludes tracks which have
-    // an originalReleaseTrack update value set, which means even though it does
+    // By definition, find.trackMainReleasesOnly excludes tracks which have
+    // an mainReleaseTrack update value set, which means even though it does
     // still access each of tracks' `alwaysReferenceByDirectory` property, it
     // won't access that of *this* track - it will never proceed past the
     // `exitWithoutDependency` step directly above, so there's no opportunity
     // for recursion.
     withResolvedReference({
-      ref: 'originalReleaseTrack',
+      ref: 'mainReleaseTrack',
       data: 'trackData',
-      find: input.value(find.trackOriginalReleasesOnly),
+      find: input.value(find.trackMainReleasesOnly),
     }).outputs({
-      '#resolvedReference': '#originalRelease',
+      '#resolvedReference': '#mainRelease',
     }),
 
     exitWithoutDependency({
-      dependency: '#originalRelease',
+      dependency: '#mainRelease',
       value: input.value(false),
     }),
 
     withPropertyFromObject({
-      object: '#originalRelease',
+      object: '#mainRelease',
       property: input.value('name'),
     }),
 
     {
-      dependencies: ['name', '#originalRelease.name'],
+      dependencies: ['name', '#mainRelease.name'],
       compute: (continuation, {
         name,
-        ['#originalRelease.name']: originalName,
+        ['#mainRelease.name']: mainReleaseName,
       }) => continuation({
-        ['#alwaysReferenceByDirectory']: name === originalName,
+        ['#alwaysReferenceByDirectory']:
+          name === mainReleaseName,
       }),
     },
   ],
diff --git a/src/data/composite/things/track/withContainingTrackSection.js b/src/data/composite/things/track/withContainingTrackSection.js
index b2e5f2b3..3d4d081e 100644
--- a/src/data/composite/things/track/withContainingTrackSection.js
+++ b/src/data/composite/things/track/withContainingTrackSection.js
@@ -1,63 +1,20 @@
 // Gets the track section containing this track from its album's track list.
-// If notFoundMode is set to 'exit', this will early exit if the album can't be
-// found or if none of its trackSections includes the track for some reason.
 
-import {input, templateCompositeFrom} from '#composite';
-import {is} from '#validators';
+import {templateCompositeFrom} from '#composite';
 
-import withPropertyFromAlbum from './withPropertyFromAlbum.js';
+import {withUniqueReferencingThing} from '#composite/wiki-data';
+import {soupyReverse} from '#composite/wiki-properties';
 
 export default templateCompositeFrom({
   annotation: `withContainingTrackSection`,
 
-  inputs: {
-    notFoundMode: input({
-      validate: is('exit', 'null'),
-      defaultValue: 'null',
-    }),
-  },
-
   outputs: ['#trackSection'],
 
   steps: () => [
-    withPropertyFromAlbum({
-      property: input.value('trackSections'),
-      notFoundMode: input('notFoundMode'),
+    withUniqueReferencingThing({
+      reverse: soupyReverse.input('trackSectionsWhichInclude'),
+    }).outputs({
+      ['#uniqueReferencingThing']: '#trackSection',
     }),
-
-    {
-      dependencies: [
-        input.myself(),
-        input('notFoundMode'),
-        '#album.trackSections',
-      ],
-
-      compute(continuation, {
-        [input.myself()]: track,
-        [input('notFoundMode')]: notFoundMode,
-        ['#album.trackSections']: trackSections,
-      }) {
-        if (!trackSections) {
-          return continuation.raiseOutput({
-            ['#trackSection']: null,
-          });
-        }
-
-        const trackSection =
-          trackSections.find(({tracks}) => tracks.includes(track));
-
-        if (trackSection) {
-          return continuation.raiseOutput({
-            ['#trackSection']: trackSection,
-          });
-        } else if (notFoundMode === 'exit') {
-          return continuation.exit(null);
-        } else {
-          return continuation.raiseOutput({
-            ['#trackSection']: null,
-          });
-        }
-      },
-    },
   ],
 });
diff --git a/src/data/composite/things/track/withCoverArtistContribs.js b/src/data/composite/things/track/withCoverArtistContribs.js
new file mode 100644
index 00000000..9057cfeb
--- /dev/null
+++ b/src/data/composite/things/track/withCoverArtistContribs.js
@@ -0,0 +1,73 @@
+import {input, templateCompositeFrom} from '#composite';
+import {isContributionList} from '#validators';
+
+import {exposeDependencyOrContinue} from '#composite/control-flow';
+
+import {
+  withRecontextualizedContributionList,
+  withRedatedContributionList,
+  withResolvedContribs,
+} from '#composite/wiki-data';
+
+import exitWithoutUniqueCoverArt from './exitWithoutUniqueCoverArt.js';
+import withPropertyFromAlbum from './withPropertyFromAlbum.js';
+import withTrackArtDate from './withTrackArtDate.js';
+
+export default templateCompositeFrom({
+  annotation: `withCoverArtistContribs`,
+
+  inputs: {
+    from: input({
+      defaultDependency: 'coverArtistContribs',
+      validate: isContributionList,
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#coverArtistContribs'],
+
+  steps: () => [
+    exitWithoutUniqueCoverArt({
+      value: input.value([]),
+    }),
+
+    withTrackArtDate(),
+
+    withResolvedContribs({
+      from: input('from'),
+      thingProperty: input.value('coverArtistContribs'),
+      artistProperty: input.value('trackCoverArtistContributions'),
+      date: '#trackArtDate',
+    }).outputs({
+      '#resolvedContribs': '#coverArtistContribs',
+    }),
+
+    exposeDependencyOrContinue({
+      dependency: '#coverArtistContribs',
+      mode: input.value('empty'),
+    }),
+
+    withPropertyFromAlbum({
+      property: input.value('trackCoverArtistContribs'),
+    }),
+
+    withRecontextualizedContributionList({
+      list: '#album.trackCoverArtistContribs',
+      artistProperty: input.value('trackCoverArtistContributions'),
+    }),
+
+    withRedatedContributionList({
+      list: '#album.trackCoverArtistContribs',
+      date: '#trackArtDate',
+    }),
+
+    {
+      dependencies: ['#album.trackCoverArtistContribs'],
+      compute: (continuation, {
+        ['#album.trackCoverArtistContribs']: coverArtistContribs,
+      }) => continuation({
+        ['#coverArtistContribs']: coverArtistContribs,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/track/withDate.js b/src/data/composite/things/track/withDate.js
new file mode 100644
index 00000000..b5a770e9
--- /dev/null
+++ b/src/data/composite/things/track/withDate.js
@@ -0,0 +1,34 @@
+// Gets the track's own date. This is either its dateFirstReleased property
+// or, if unset, the album's date.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import withPropertyFromAlbum from './withPropertyFromAlbum.js';
+
+export default templateCompositeFrom({
+  annotation: `withDate`,
+
+  outputs: ['#date'],
+
+  steps: () => [
+    {
+      dependencies: ['dateFirstReleased'],
+      compute: (continuation, {dateFirstReleased}) =>
+        (dateFirstReleased
+          ? continuation.raiseOutput({'#date': dateFirstReleased})
+          : continuation()),
+    },
+
+    withPropertyFromAlbum({
+      property: input.value('date'),
+    }),
+
+    {
+      dependencies: ['#album.date'],
+      compute: (continuation, {['#album.date']: albumDate}) =>
+        (albumDate
+          ? continuation.raiseOutput({'#date': albumDate})
+          : continuation.raiseOutput({'#date': null})),
+    },
+  ],
+})
diff --git a/src/data/composite/things/track/withDirectorySuffix.js b/src/data/composite/things/track/withDirectorySuffix.js
new file mode 100644
index 00000000..c063e158
--- /dev/null
+++ b/src/data/composite/things/track/withDirectorySuffix.js
@@ -0,0 +1,36 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+import withPropertyFromAlbum from './withPropertyFromAlbum.js';
+import withSuffixDirectoryFromAlbum from './withSuffixDirectoryFromAlbum.js';
+
+export default templateCompositeFrom({
+  annotation: `withDirectorySuffix`,
+
+  outputs: ['#directorySuffix'],
+
+  steps: () => [
+    withSuffixDirectoryFromAlbum(),
+
+    raiseOutputWithoutDependency({
+      dependency: '#suffixDirectoryFromAlbum',
+      mode: input.value('falsy'),
+      output: input.value({['#directorySuffix']: null}),
+    }),
+
+    withPropertyFromAlbum({
+      property: input.value('directorySuffix'),
+    }),
+
+    {
+      dependencies: ['#album.directorySuffix'],
+      compute: (continuation, {
+        ['#album.directorySuffix']: directorySuffix,
+      }) => continuation({
+        ['#directorySuffix']:
+          directorySuffix,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/track/withHasUniqueCoverArt.js b/src/data/composite/things/track/withHasUniqueCoverArt.js
index 96078d5f..85d3b92a 100644
--- a/src/data/composite/things/track/withHasUniqueCoverArt.js
+++ b/src/data/composite/things/track/withHasUniqueCoverArt.js
@@ -5,11 +5,18 @@
 // or a placeholder. (This property is named hasUniqueCoverArt instead of
 // the usual hasCoverArt to emphasize that it does not inherit from the
 // album.)
+//
+// withHasUniqueCoverArt is based only around the presence of *specified*
+// cover artist contributions, not whether the references to artists on those
+// contributions actually resolve to anything. It completely evades interacting
+// with find/replace.
 
 import {input, templateCompositeFrom} from '#composite';
-import {empty} from '#sugar';
 
-import {withResolvedContribs} from '#composite/wiki-data';
+import {raiseOutputWithoutDependency, withResultOfAvailabilityCheck}
+  from '#composite/control-flow';
+import {fillMissingListItems, withFlattenedList, withPropertyFromList}
+  from '#composite/data';
 
 import withPropertyFromAlbum from './withPropertyFromAlbum.js';
 
@@ -29,33 +36,73 @@ export default templateCompositeFrom({
           : continuation()),
     },
 
-    withResolvedContribs({from: 'coverArtistContribs'}),
+    withResultOfAvailabilityCheck({
+      from: 'coverArtistContribs',
+      mode: input.value('empty'),
+    }),
 
     {
-      dependencies: ['#resolvedContribs'],
+      dependencies: ['#availability'],
       compute: (continuation, {
-        ['#resolvedContribs']: contribsFromTrack,
+        ['#availability']: availability,
       }) =>
-        (empty(contribsFromTrack)
-          ? continuation()
-          : continuation.raiseOutput({
+        (availability
+          ? continuation.raiseOutput({
               ['#hasUniqueCoverArt']: true,
-            })),
+            })
+          : continuation()),
     },
 
     withPropertyFromAlbum({
       property: input.value('trackCoverArtistContribs'),
+      internal: input.value(true),
+    }),
+
+    withResultOfAvailabilityCheck({
+      from: '#album.trackCoverArtistContribs',
+      mode: input.value('empty'),
     }),
 
     {
-      dependencies: ['#album.trackCoverArtistContribs'],
+      dependencies: ['#availability'],
       compute: (continuation, {
-        ['#album.trackCoverArtistContribs']: contribsFromAlbum,
+        ['#availability']: availability,
       }) =>
-        continuation.raiseOutput({
-          ['#hasUniqueCoverArt']:
-            !empty(contribsFromAlbum),
-        }),
+        (availability
+          ? continuation.raiseOutput({
+              ['#hasUniqueCoverArt']: true,
+            })
+          : continuation()),
     },
+
+    raiseOutputWithoutDependency({
+      dependency: 'trackArtworks',
+      mode: input.value('empty'),
+      output: input.value({'#hasUniqueCoverArt': false}),
+    }),
+
+    withPropertyFromList({
+      list: 'trackArtworks',
+      property: input.value('artistContribs'),
+      internal: input.value(true),
+    }),
+
+    // Since we're getting the update value for each artwork's artistContribs,
+    // it may not be set at all, and in that case won't be exposing as [].
+    fillMissingListItems({
+      list: '#trackArtworks.artistContribs',
+      fill: input.value([]),
+    }),
+
+    withFlattenedList({
+      list: '#trackArtworks.artistContribs',
+    }),
+
+    withResultOfAvailabilityCheck({
+      from: '#flattenedList',
+      mode: input.value('empty'),
+    }).outputs({
+      '#availability': '#hasUniqueCoverArt',
+    }),
   ],
 });
diff --git a/src/data/composite/things/track/withOriginalRelease.js b/src/data/composite/things/track/withMainRelease.js
index c7f49657..3a91edae 100644
--- a/src/data/composite/things/track/withOriginalRelease.js
+++ b/src/data/composite/things/track/withMainRelease.js
@@ -1,62 +1,54 @@
-// Just includes the original release of this track as a dependency.
-// If this track isn't a rerelease, then it'll provide null, unless the
-// {selfIfOriginal} option is set, in which case it'll provide this track
-// itself. This will early exit (with notFoundValue) if the original release
+// Just includes the main release of this track as a dependency.
+// If this track isn't a secondary release, then it'll provide null, unless
+// the {selfIfMain} option is set, in which case it'll provide this track
+// itself. This will early exit (with notFoundValue) if the main release
 // is specified by reference and that reference doesn't resolve to anything.
 
 import {input, templateCompositeFrom} from '#composite';
-import find from '#find';
-import {validateWikiData} from '#validators';
 
 import {exitWithoutDependency, withResultOfAvailabilityCheck}
   from '#composite/control-flow';
 import {withResolvedReference} from '#composite/wiki-data';
+import {soupyFind} from '#composite/wiki-properties';
 
 export default templateCompositeFrom({
-  annotation: `withOriginalRelease`,
+  annotation: `withMainRelease`,
 
   inputs: {
-    selfIfOriginal: input({type: 'boolean', defaultValue: false}),
-
-    data: input({
-      validate: validateWikiData({referenceType: 'track'}),
-      defaultDependency: 'trackData',
-    }),
-
+    selfIfMain: input({type: 'boolean', defaultValue: false}),
     notFoundValue: input({defaultValue: null}),
   },
 
-  outputs: ['#originalRelease'],
+  outputs: ['#mainRelease'],
 
   steps: () => [
     withResultOfAvailabilityCheck({
-      from: 'originalReleaseTrack',
+      from: 'mainReleaseTrack',
     }),
 
     {
       dependencies: [
         input.myself(),
-        input('selfIfOriginal'),
+        input('selfIfMain'),
         '#availability',
       ],
 
       compute: (continuation, {
         [input.myself()]: track,
-        [input('selfIfOriginal')]: selfIfOriginal,
+        [input('selfIfMain')]: selfIfMain,
         '#availability': availability,
       }) =>
         (availability
           ? continuation()
           : continuation.raiseOutput({
-              ['#originalRelease']:
-                (selfIfOriginal ? track : null),
+              ['#mainRelease']:
+                (selfIfMain ? track : null),
             })),
     },
 
     withResolvedReference({
-      ref: 'originalReleaseTrack',
-      data: input('data'),
-      find: input.value(find.track),
+      ref: 'mainReleaseTrack',
+      find: soupyFind.input('track'),
     }),
 
     exitWithoutDependency({
@@ -71,7 +63,7 @@ export default templateCompositeFrom({
         ['#resolvedReference']: resolvedReference,
       }) =>
         continuation({
-          ['#originalRelease']: resolvedReference,
+          ['#mainRelease']: resolvedReference,
         }),
     },
   ],
diff --git a/src/data/composite/things/track/withOtherReleases.js b/src/data/composite/things/track/withOtherReleases.js
index f8c1c3f0..bb3e8983 100644
--- a/src/data/composite/things/track/withOtherReleases.js
+++ b/src/data/composite/things/track/withOtherReleases.js
@@ -1,8 +1,9 @@
-import {input, templateCompositeFrom} from '#composite';
+// Gets all releases of the current track *except* this track itself;
+// in other words, all other releases of the current track.
 
-import {exitWithoutDependency} from '#composite/control-flow';
+import {input, templateCompositeFrom} from '#composite';
 
-import withOriginalRelease from './withOriginalRelease.js';
+import withAllReleases from './withAllReleases.js';
 
 export default templateCompositeFrom({
   annotation: `withOtherReleases`,
@@ -10,31 +11,16 @@ export default templateCompositeFrom({
   outputs: ['#otherReleases'],
 
   steps: () => [
-    exitWithoutDependency({
-      dependency: 'trackData',
-      mode: input.value('empty'),
-    }),
-
-    withOriginalRelease({
-      selfIfOriginal: input.value(true),
-      notFoundValue: input.value([]),
-    }),
+    withAllReleases(),
 
     {
-      dependencies: [input.myself(), '#originalRelease', 'trackData'],
+      dependencies: [input.myself(), '#allReleases'],
       compute: (continuation, {
         [input.myself()]: thisTrack,
-        ['#originalRelease']: originalRelease,
-        trackData,
+        ['#allReleases']: allReleases,
       }) => continuation({
         ['#otherReleases']:
-          (originalRelease === thisTrack
-            ? []
-            : [originalRelease])
-            .concat(trackData.filter(track =>
-              track !== originalRelease &&
-              track !== thisTrack &&
-              track.originalReleaseTrack === originalRelease)),
+          allReleases.filter(track => track !== thisTrack),
       }),
     },
   ],
diff --git a/src/data/composite/things/track/withPropertyFromAlbum.js b/src/data/composite/things/track/withPropertyFromAlbum.js
index b236a6e8..a203c2e7 100644
--- a/src/data/composite/things/track/withPropertyFromAlbum.js
+++ b/src/data/composite/things/track/withPropertyFromAlbum.js
@@ -1,25 +1,16 @@
 // Gets a single property from this track's album, providing it as the same
-// property name prefixed with '#album.' (by default). If the track's album
-// isn't available, then by default, the property will be provided as null;
-// set {notFoundMode: 'exit'} to early exit instead.
+// property name prefixed with '#album.' (by default).
 
 import {input, templateCompositeFrom} from '#composite';
-import {is} from '#validators';
 
 import {withPropertyFromObject} from '#composite/data';
 
-import withAlbum from './withAlbum.js';
-
 export default templateCompositeFrom({
   annotation: `withPropertyFromAlbum`,
 
   inputs: {
     property: input.staticValue({type: 'string'}),
-
-    notFoundMode: input({
-      validate: is('exit', 'null'),
-      defaultValue: 'null',
-    }),
+    internal: input({type: 'boolean', defaultValue: false}),
   },
 
   outputs: ({
@@ -27,13 +18,21 @@ export default templateCompositeFrom({
   }) => ['#album.' + property],
 
   steps: () => [
-    withAlbum({
-      notFoundMode: input('notFoundMode'),
-    }),
+    // XXX: This is a ridiculous hack considering `defaultValue` above.
+    // If we were certain what was up, we'd just get around to fixing it LOL
+    {
+      dependencies: [input('internal')],
+      compute: (continuation, {
+        [input('internal')]: internal,
+      }) => continuation({
+        ['#internal']: internal ?? false,
+      }),
+    },
 
     withPropertyFromObject({
-      object: '#album',
+      object: 'album',
       property: input('property'),
+      internal: '#internal',
     }),
 
     {
diff --git a/src/data/composite/things/track/withPropertyFromMainRelease.js b/src/data/composite/things/track/withPropertyFromMainRelease.js
new file mode 100644
index 00000000..393a4c63
--- /dev/null
+++ b/src/data/composite/things/track/withPropertyFromMainRelease.js
@@ -0,0 +1,86 @@
+// Provides a value inherited from the main release, if applicable, and a
+// flag indicating if this track is a secondary release or not.
+//
+// Like withMainRelease, this will early exit (with notFoundValue) if the
+// main release is specified by reference and that reference doesn't
+// resolve to anything.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {withResultOfAvailabilityCheck} from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+
+import withMainRelease from './withMainRelease.js';
+
+export default templateCompositeFrom({
+  annotation: `inheritFromMainRelease`,
+
+  inputs: {
+    property: input({type: 'string'}),
+
+    notFoundValue: input({
+      defaultValue: null,
+    }),
+  },
+
+  outputs: ({
+    [input.staticValue('property')]: property,
+  }) =>
+    ['#isSecondaryRelease'].concat(
+      (property
+        ? ['#mainRelease.' + property]
+        : ['#mainReleaseValue'])),
+
+  steps: () => [
+    withMainRelease({
+      notFoundValue: input('notFoundValue'),
+    }),
+
+    withResultOfAvailabilityCheck({
+      from: '#mainRelease',
+    }),
+
+    {
+      dependencies: [
+        '#availability',
+        input.staticValue('property'),
+      ],
+
+      compute: (continuation, {
+        ['#availability']: availability,
+        [input.staticValue('property')]: property,
+      }) =>
+        (availability
+          ? continuation()
+          : continuation.raiseOutput(
+              Object.assign(
+                {'#isSecondaryRelease': false},
+                (property
+                  ? {['#mainRelease.' + property]: null}
+                  : {'#mainReleaseValue': null})))),
+    },
+
+    withPropertyFromObject({
+      object: '#mainRelease',
+      property: input('property'),
+    }),
+
+    {
+      dependencies: [
+        '#value',
+        input.staticValue('property'),
+      ],
+
+      compute: (continuation, {
+        ['#value']: value,
+        [input.staticValue('property')]: property,
+      }) =>
+        continuation.raiseOutput(
+          Object.assign(
+            {'#isSecondaryRelease': true},
+            (property
+              ? {['#mainRelease.' + property]: value}
+              : {'#mainReleaseValue': value}))),
+    },
+  ],
+});
diff --git a/src/data/composite/things/track/withSuffixDirectoryFromAlbum.js b/src/data/composite/things/track/withSuffixDirectoryFromAlbum.js
new file mode 100644
index 00000000..7159a3f4
--- /dev/null
+++ b/src/data/composite/things/track/withSuffixDirectoryFromAlbum.js
@@ -0,0 +1,53 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {withResultOfAvailabilityCheck} from '#composite/control-flow';
+
+import withPropertyFromAlbum from './withPropertyFromAlbum.js';
+
+export default templateCompositeFrom({
+  annotation: `withSuffixDirectoryFromAlbum`,
+
+  inputs: {
+    flagValue: input({
+      defaultDependency: 'suffixDirectoryFromAlbum',
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#suffixDirectoryFromAlbum'],
+
+  steps: () => [
+    withResultOfAvailabilityCheck({
+      from: 'suffixDirectoryFromAlbum',
+    }),
+
+    {
+      dependencies: [
+        '#availability',
+        'suffixDirectoryFromAlbum'
+      ],
+
+      compute: (continuation, {
+        ['#availability']: availability,
+        ['suffixDirectoryFromAlbum']: flagValue,
+      }) =>
+        (availability
+          ? continuation.raiseOutput({['#suffixDirectoryFromAlbum']: flagValue})
+          : continuation()),
+    },
+
+    withPropertyFromAlbum({
+      property: input.value('suffixTrackDirectories'),
+    }),
+
+    {
+      dependencies: ['#album.suffixTrackDirectories'],
+      compute: (continuation, {
+        ['#album.suffixTrackDirectories']: suffixTrackDirectories,
+      }) => continuation({
+        ['#suffixDirectoryFromAlbum']:
+          suffixTrackDirectories,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/track/withTrackArtDate.js b/src/data/composite/things/track/withTrackArtDate.js
new file mode 100644
index 00000000..9b7b61c7
--- /dev/null
+++ b/src/data/composite/things/track/withTrackArtDate.js
@@ -0,0 +1,60 @@
+import {input, templateCompositeFrom} from '#composite';
+import {isDate} from '#validators';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+import withDate from './withDate.js';
+import withHasUniqueCoverArt from './withHasUniqueCoverArt.js';
+import withPropertyFromAlbum from './withPropertyFromAlbum.js';
+
+export default templateCompositeFrom({
+  annotation: `withTrackArtDate`,
+
+  inputs: {
+    from: input({
+      validate: isDate,
+      defaultDependency: 'coverArtDate',
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#trackArtDate'],
+
+  steps: () => [
+    withHasUniqueCoverArt(),
+
+    raiseOutputWithoutDependency({
+      dependency: '#hasUniqueCoverArt',
+      mode: input.value('falsy'),
+      output: input.value({'#trackArtDate': null}),
+    }),
+
+    {
+      dependencies: [input('from')],
+      compute: (continuation, {
+        [input('from')]: from,
+      }) =>
+        (from
+          ? continuation.raiseOutput({'#trackArtDate': from})
+          : continuation()),
+    },
+
+    withPropertyFromAlbum({
+      property: input.value('trackArtDate'),
+    }),
+
+    {
+      dependencies: ['#album.trackArtDate'],
+      compute: (continuation, {
+        ['#album.trackArtDate']: albumTrackArtDate,
+      }) =>
+        (albumTrackArtDate
+          ? continuation.raiseOutput({'#trackArtDate': albumTrackArtDate})
+          : continuation()),
+    },
+
+    withDate().outputs({
+      '#date': '#trackArtDate',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/track/withTrackNumber.js b/src/data/composite/things/track/withTrackNumber.js
new file mode 100644
index 00000000..61428e8c
--- /dev/null
+++ b/src/data/composite/things/track/withTrackNumber.js
@@ -0,0 +1,50 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withIndexInList, withPropertiesFromObject} from '#composite/data';
+
+import withContainingTrackSection from './withContainingTrackSection.js';
+
+export default templateCompositeFrom({
+  annotation: `withTrackNumber`,
+
+  outputs: ['#trackNumber'],
+
+  steps: () => [
+    withContainingTrackSection(),
+
+    // Zero is the fallback, not one, but in most albums the first track
+    // (and its intended output by this composition) will be one.
+    raiseOutputWithoutDependency({
+      dependency: '#trackSection',
+      output: input.value({'#trackNumber': 0}),
+    }),
+
+    withPropertiesFromObject({
+      object: '#trackSection',
+      properties: input.value(['tracks', 'startCountingFrom']),
+    }),
+
+    withIndexInList({
+      list: '#trackSection.tracks',
+      item: input.myself(),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#index',
+      output: input.value({'#trackNumber': 0}),
+    }),
+
+    {
+      dependencies: ['#trackSection.startCountingFrom', '#index'],
+      compute: (continuation, {
+        ['#trackSection.startCountingFrom']: startCountingFrom,
+        ['#index']: index,
+      }) => continuation({
+        ['#trackNumber']:
+          startCountingFrom +
+          index,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/exitWithoutContribs.js b/src/data/composite/wiki-data/exitWithoutContribs.js
index 2c8219fc..cf52950d 100644
--- a/src/data/composite/wiki-data/exitWithoutContribs.js
+++ b/src/data/composite/wiki-data/exitWithoutContribs.js
@@ -24,6 +24,7 @@ export default templateCompositeFrom({
   steps: () => [
     withResolvedContribs({
       from: input('contribs'),
+      date: input.value(null),
     }),
 
     // TODO: Fairly certain exitWithoutDependency would be sufficient here.
diff --git a/src/data/composite/wiki-data/gobbleSoupyFind.js b/src/data/composite/wiki-data/gobbleSoupyFind.js
new file mode 100644
index 00000000..aec3f5b1
--- /dev/null
+++ b/src/data/composite/wiki-data/gobbleSoupyFind.js
@@ -0,0 +1,39 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {withPropertyFromObject} from '#composite/data';
+
+import inputSoupyFind, {getSoupyFindInputKey} from './inputSoupyFind.js';
+
+export default templateCompositeFrom({
+  annotation: `gobbleSoupyFind`,
+
+  inputs: {
+    find: inputSoupyFind(),
+  },
+
+  outputs: ['#find'],
+
+  steps: () => [
+    {
+      dependencies: [input('find')],
+      compute: (continuation, {
+        [input('find')]: find,
+      }) =>
+        (typeof find === 'function'
+          ? continuation.raiseOutput({
+              ['#find']: find,
+            })
+          : continuation({
+              ['#key']:
+                getSoupyFindInputKey(find),
+            })),
+    },
+
+    withPropertyFromObject({
+      object: 'find',
+      property: '#key',
+    }).outputs({
+      '#value': '#find',
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-data/gobbleSoupyReverse.js b/src/data/composite/wiki-data/gobbleSoupyReverse.js
new file mode 100644
index 00000000..86a1061c
--- /dev/null
+++ b/src/data/composite/wiki-data/gobbleSoupyReverse.js
@@ -0,0 +1,39 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {withPropertyFromObject} from '#composite/data';
+
+import inputSoupyReverse, {getSoupyReverseInputKey} from './inputSoupyReverse.js';
+
+export default templateCompositeFrom({
+  annotation: `gobbleSoupyReverse`,
+
+  inputs: {
+    reverse: inputSoupyReverse(),
+  },
+
+  outputs: ['#reverse'],
+
+  steps: () => [
+    {
+      dependencies: [input('reverse')],
+      compute: (continuation, {
+        [input('reverse')]: reverse,
+      }) =>
+        (typeof reverse === 'function'
+          ? continuation.raiseOutput({
+              ['#reverse']: reverse,
+            })
+          : continuation({
+              ['#key']:
+                getSoupyReverseInputKey(reverse),
+            })),
+    },
+
+    withPropertyFromObject({
+      object: 'reverse',
+      property: '#key',
+    }).outputs({
+      '#value': '#reverse',
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-data/helpers/withDirectoryFromName.js b/src/data/composite/wiki-data/helpers/withDirectoryFromName.js
new file mode 100644
index 00000000..f85dae16
--- /dev/null
+++ b/src/data/composite/wiki-data/helpers/withDirectoryFromName.js
@@ -0,0 +1,41 @@
+// Compute a directory from a name.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {isName} from '#validators';
+import {getKebabCase} from '#wiki-data';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+export default templateCompositeFrom({
+  annotation: `withDirectoryFromName`,
+
+  inputs: {
+    name: input({
+      validate: isName,
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#directory'],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: input('name'),
+      mode: input.value('falsy'),
+      output: input.value({
+        ['#directory']: null,
+      }),
+    }),
+
+    {
+      dependencies: [input('name')],
+      compute: (continuation, {
+        [input('name')]: name,
+      }) => continuation({
+        ['#directory']:
+          getKebabCase(name),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/helpers/withResolvedReverse.js b/src/data/composite/wiki-data/helpers/withResolvedReverse.js
new file mode 100644
index 00000000..818f60b7
--- /dev/null
+++ b/src/data/composite/wiki-data/helpers/withResolvedReverse.js
@@ -0,0 +1,40 @@
+// Actually execute a reverse function.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import inputWikiData from '../inputWikiData.js';
+
+export default templateCompositeFrom({
+  annotation: `withReverseReferenceList`,
+
+  inputs: {
+    data: inputWikiData({allowMixedTypes: true}),
+    reverse: input({type: 'function'}),
+    options: input({type: 'object', defaultValue: null}),
+  },
+
+  outputs: ['#resolvedReverse'],
+
+  steps: () => [
+    {
+      dependencies: [
+        input.myself(),
+        input('data'),
+        input('reverse'),
+        input('options'),
+      ],
+
+      compute: (continuation, {
+        [input.myself()]: myself,
+        [input('data')]: data,
+        [input('reverse')]: reverseFunction,
+        [input('options')]: opts,
+      }) => continuation({
+        ['#resolvedReverse']:
+          (data
+            ? reverseFunction(myself, data, opts)
+            : reverseFunction(myself, opts)),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/helpers/withSimpleDirectory.js b/src/data/composite/wiki-data/helpers/withSimpleDirectory.js
new file mode 100644
index 00000000..08ca3bfc
--- /dev/null
+++ b/src/data/composite/wiki-data/helpers/withSimpleDirectory.js
@@ -0,0 +1,52 @@
+// A "simple" directory, based only on the already-provided directory, if
+// available, or the provided name.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {isDirectory, isName} from '#validators';
+
+import {withResultOfAvailabilityCheck} from '#composite/control-flow';
+
+import withDirectoryFromName from './withDirectoryFromName.js';
+
+export default templateCompositeFrom({
+  annotation: `withSimpleDirectory`,
+
+  inputs: {
+    directory: input({
+      validate: isDirectory,
+      defaultDependency: 'directory',
+      acceptsNull: true,
+    }),
+
+    name: input({
+      validate: isName,
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#directory'],
+
+  steps: () => [
+    withResultOfAvailabilityCheck({
+      from: input('directory'),
+    }),
+
+    {
+      dependencies: ['#availability', input('directory')],
+      compute: (continuation, {
+        ['#availability']: availability,
+        [input('directory')]: directory,
+      }) =>
+        (availability
+          ? continuation.raiseOutput({
+              ['#directory']: directory
+            })
+          : continuation()),
+    },
+
+    withDirectoryFromName({
+      name: input('name'),
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-data/index.js b/src/data/composite/wiki-data/index.js
index 3ccfa75d..38afc2ac 100644
--- a/src/data/composite/wiki-data/index.js
+++ b/src/data/composite/wiki-data/index.js
@@ -5,11 +5,25 @@
 //
 
 export {default as exitWithoutContribs} from './exitWithoutContribs.js';
+export {default as gobbleSoupyFind} from './gobbleSoupyFind.js';
+export {default as gobbleSoupyReverse} from './gobbleSoupyReverse.js';
+export {default as inputNotFoundMode} from './inputNotFoundMode.js';
+export {default as inputSoupyFind} from './inputSoupyFind.js';
+export {default as inputSoupyReverse} from './inputSoupyReverse.js';
 export {default as inputWikiData} from './inputWikiData.js';
-export {default as withParsedCommentaryEntries} from './withParsedCommentaryEntries.js';
+export {default as splitContentNodesAround} from './splitContentNodesAround.js';
+export {default as withClonedThings} from './withClonedThings.js';
+export {default as withConstitutedArtwork} from './withConstitutedArtwork.js';
+export {default as withContentNodes} from './withContentNodes.js';
+export {default as withContributionListSums} from './withContributionListSums.js';
+export {default as withCoverArtDate} from './withCoverArtDate.js';
+export {default as withDirectory} from './withDirectory.js';
+export {default as withRecontextualizedContributionList} from './withRecontextualizedContributionList.js';
+export {default as withRedatedContributionList} from './withRedatedContributionList.js';
+export {default as withResolvedAnnotatedReferenceList} from './withResolvedAnnotatedReferenceList.js';
 export {default as withResolvedContribs} from './withResolvedContribs.js';
 export {default as withResolvedReference} from './withResolvedReference.js';
 export {default as withResolvedReferenceList} from './withResolvedReferenceList.js';
-export {default as withReverseContributionList} from './withReverseContributionList.js';
 export {default as withReverseReferenceList} from './withReverseReferenceList.js';
 export {default as withThingsSortedAlphabetically} from './withThingsSortedAlphabetically.js';
+export {default as withUniqueReferencingThing} from './withUniqueReferencingThing.js';
diff --git a/src/data/composite/wiki-data/inputNotFoundMode.js b/src/data/composite/wiki-data/inputNotFoundMode.js
new file mode 100644
index 00000000..d16b2472
--- /dev/null
+++ b/src/data/composite/wiki-data/inputNotFoundMode.js
@@ -0,0 +1,9 @@
+import {input} from '#composite';
+import {is} from '#validators';
+
+export default function inputNotFoundMode() {
+  return input({
+    validate: is('exit', 'filter', 'null'),
+    defaultValue: 'filter',
+  });
+}
diff --git a/src/data/composite/wiki-data/inputSoupyFind.js b/src/data/composite/wiki-data/inputSoupyFind.js
new file mode 100644
index 00000000..020f4990
--- /dev/null
+++ b/src/data/composite/wiki-data/inputSoupyFind.js
@@ -0,0 +1,28 @@
+import {input} from '#composite';
+import {anyOf, isFunction, isString} from '#validators';
+
+function inputSoupyFind() {
+  return input({
+    validate:
+      anyOf(
+        isFunction,
+        val => {
+          isString(val);
+
+          if (!val.startsWith('_soupyFind:')) {
+            throw new Error(`Expected soupyFind.input() token`);
+          }
+
+          return true;
+        }),
+  });
+}
+
+inputSoupyFind.input = key =>
+  input.value('_soupyFind:' + key);
+
+export default inputSoupyFind;
+
+export function getSoupyFindInputKey(value) {
+  return value.slice('_soupyFind:'.length);
+}
diff --git a/src/data/composite/wiki-data/inputSoupyReverse.js b/src/data/composite/wiki-data/inputSoupyReverse.js
new file mode 100644
index 00000000..0b0a23fe
--- /dev/null
+++ b/src/data/composite/wiki-data/inputSoupyReverse.js
@@ -0,0 +1,32 @@
+import {input} from '#composite';
+import {anyOf, isFunction, isString} from '#validators';
+
+function inputSoupyReverse() {
+  return input({
+    validate:
+      anyOf(
+        isFunction,
+        val => {
+          isString(val);
+
+          if (!val.startsWith('_soupyReverse:')) {
+            throw new Error(`Expected soupyReverse.input() token`);
+          }
+
+          return true;
+        }),
+  });
+}
+
+inputSoupyReverse.input = key =>
+  input.value('_soupyReverse:' + key);
+
+export default inputSoupyReverse;
+
+export function getSoupyReverseInputKey(value) {
+  return value.slice('_soupyReverse:'.length).replace(/\.unique$/, '');
+}
+
+export function doesSoupyReverseInputWantUnique(value) {
+  return value.endsWith('.unique');
+}
diff --git a/src/data/composite/wiki-data/inputWikiData.js b/src/data/composite/wiki-data/inputWikiData.js
index cf7a7c2c..b9021986 100644
--- a/src/data/composite/wiki-data/inputWikiData.js
+++ b/src/data/composite/wiki-data/inputWikiData.js
@@ -12,6 +12,6 @@ export default function inputWikiData({
 } = {}) {
   return input({
     validate: validateWikiData({referenceType, allowMixedTypes}),
-    acceptsNull: true,
+    defaultValue: null,
   });
 }
diff --git a/src/data/composite/wiki-data/raiseResolvedReferenceList.js b/src/data/composite/wiki-data/raiseResolvedReferenceList.js
new file mode 100644
index 00000000..613b002b
--- /dev/null
+++ b/src/data/composite/wiki-data/raiseResolvedReferenceList.js
@@ -0,0 +1,96 @@
+// Concludes compositions like withResolvedReferenceList, which share behavior
+// in processing the resolved results before continuing further.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {withFilteredList} from '#composite/data';
+
+import inputNotFoundMode from './inputNotFoundMode.js';
+
+export default templateCompositeFrom({
+  inputs: {
+    notFoundMode: inputNotFoundMode(),
+
+    results: input({type: 'array'}),
+    filter: input({type: 'array'}),
+
+    exitValue: input({defaultValue: []}),
+
+    outputs: input.staticValue({type: 'string'}),
+  },
+
+  outputs: ({
+    [input.staticValue('outputs')]: outputs,
+  }) => [outputs],
+
+  steps: () => [
+    {
+      dependencies: [
+        input('results'),
+        input('filter'),
+        input('outputs'),
+      ],
+
+      compute: (continuation, {
+        [input('results')]: results,
+        [input('filter')]: filter,
+        [input('outputs')]: outputs,
+      }) =>
+        (filter.every(keep => keep)
+          ? continuation.raiseOutput({[outputs]: results})
+          : continuation()),
+    },
+
+    {
+      dependencies: [
+        input('notFoundMode'),
+        input('exitValue'),
+      ],
+
+      compute: (continuation, {
+        [input('notFoundMode')]: notFoundMode,
+        [input('exitValue')]: exitValue,
+      }) =>
+        (notFoundMode === 'exit'
+          ? continuation.exit(exitValue)
+          : continuation()),
+    },
+
+    {
+      dependencies: [
+        input('results'),
+        input('notFoundMode'),
+        input('outputs'),
+      ],
+
+      compute: (continuation, {
+        [input('results')]: results,
+        [input('notFoundMode')]: notFoundMode,
+        [input('outputs')]: outputs,
+      }) =>
+        (notFoundMode === 'null'
+          ? continuation.raiseOutput({[outputs]: results})
+          : continuation()),
+    },
+
+    withFilteredList({
+      list: input('results'),
+      filter: input('filter'),
+    }),
+
+    {
+      dependencies: [
+        '#filteredList',
+        input('outputs'),
+      ],
+
+      compute: (continuation, {
+        ['#filteredList']: filteredList,
+        [input('outputs')]: outputs,
+      }) => continuation({
+        [outputs]:
+          filteredList,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/splitContentNodesAround.js b/src/data/composite/wiki-data/splitContentNodesAround.js
new file mode 100644
index 00000000..6648d8e1
--- /dev/null
+++ b/src/data/composite/wiki-data/splitContentNodesAround.js
@@ -0,0 +1,87 @@
+import {input, templateCompositeFrom} from '#composite';
+import {splitContentNodesAround} from '#replacer';
+import {anyOf, isFunction, validateInstanceOf} from '#validators';
+
+import {withFilteredList, withMappedList, withUnflattenedList}
+  from '#composite/data';
+
+export default templateCompositeFrom({
+  annotation: `splitContentNodesAround`,
+
+  inputs: {
+    nodes: input({type: 'array'}),
+
+    around: input({
+      validate:
+        anyOf(isFunction, validateInstanceOf(RegExp)),
+    }),
+  },
+
+  outputs: ['#contentNodeLists'],
+
+  steps: () => [
+    {
+      dependencies: [input('nodes'), input('around')],
+
+      compute: (continuation, {
+        [input('nodes')]: nodes,
+        [input('around')]: splitter,
+      }) => continuation({
+        ['#nodes']:
+          Array.from(splitContentNodesAround(nodes, splitter)),
+      }),
+    },
+
+    withMappedList({
+      list: '#nodes',
+      map: input.value(node => node.type === 'separator'),
+    }).outputs({
+      '#mappedList': '#separatorFilter',
+    }),
+
+    withMappedList({
+      list: '#separatorFilter',
+      filter: '#separatorFilter',
+      map: input.value((_node, index) => index),
+    }),
+
+    withFilteredList({
+      list: '#mappedList',
+      filter: '#separatorFilter',
+    }).outputs({
+      '#filteredList': '#separatorIndices',
+    }),
+
+    {
+      dependencies: ['#nodes', '#separatorFilter'],
+
+      compute: (continuation, {
+        ['#nodes']: nodes,
+        ['#separatorFilter']: separatorFilter,
+      }) => continuation({
+        ['#nodes']:
+          nodes.map((node, index) =>
+            (separatorFilter[index]
+              ? null
+              : node)),
+      }),
+    },
+
+    {
+      dependencies: ['#separatorIndices'],
+      compute: (continuation, {
+        ['#separatorIndices']: separatorIndices,
+      }) => continuation({
+        ['#unflattenIndices']:
+          [0, ...separatorIndices],
+      }),
+    },
+
+    withUnflattenedList({
+      list: '#nodes',
+      indices: '#unflattenIndices',
+    }).outputs({
+      '#unflattenedList': '#contentNodeLists',
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-data/withClonedThings.js b/src/data/composite/wiki-data/withClonedThings.js
new file mode 100644
index 00000000..9af6aa84
--- /dev/null
+++ b/src/data/composite/wiki-data/withClonedThings.js
@@ -0,0 +1,68 @@
+// Clones all the things in a list. If the 'assign' input is provided,
+// all new things are assigned the same specified properties. If the
+// 'assignEach' input is provided, each new thing is assigned the
+// corresponding properties.
+
+import CacheableObject from '#cacheable-object';
+import {input, templateCompositeFrom} from '#composite';
+import {isObject, sparseArrayOf} from '#validators';
+
+import {withMappedList} from '#composite/data';
+
+export default templateCompositeFrom({
+  annotation: `withClonedThings`,
+
+  inputs: {
+    things: input({type: 'array'}),
+
+    assign: input({
+      type: 'object',
+      defaultValue: null,
+    }),
+
+    assignEach: input({
+      validate: sparseArrayOf(isObject),
+      defaultValue: null,
+    }),
+  },
+
+  outputs: ['#clonedThings'],
+
+  steps: () => [
+    {
+      dependencies: [input('assign'), input('assignEach')],
+      compute: (continuation, {
+        [input('assign')]: assign,
+        [input('assignEach')]: assignEach,
+      }) => continuation({
+        ['#assignmentMap']:
+          (index) =>
+            (assign && assignEach
+              ? {...assignEach[index] ?? {}, ...assign}
+           : assignEach
+              ? assignEach[index] ?? {}
+              : assign ?? {}),
+      }),
+    },
+
+    {
+      dependencies: ['#assignmentMap'],
+      compute: (continuation, {
+        ['#assignmentMap']: assignmentMap,
+      }) => continuation({
+        ['#cloningMap']:
+          (thing, index) =>
+            Object.assign(
+              CacheableObject.clone(thing),
+              assignmentMap(index)),
+      }),
+    },
+
+    withMappedList({
+      list: input('things'),
+      map: '#cloningMap',
+    }).outputs({
+      '#mappedList': '#clonedThings',
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-data/withConstitutedArtwork.js b/src/data/composite/wiki-data/withConstitutedArtwork.js
new file mode 100644
index 00000000..28d719e2
--- /dev/null
+++ b/src/data/composite/wiki-data/withConstitutedArtwork.js
@@ -0,0 +1,60 @@
+import {input, templateCompositeFrom} from '#composite';
+import thingConstructors from '#things';
+
+export default templateCompositeFrom({
+  annotation: `withConstitutedArtwork`,
+
+  inputs: {
+    thingProperty: input({type: 'string', acceptsNull: true}),
+    dimensionsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    fileExtensionFromThingProperty: input({type: 'string', acceptsNull: true}),
+    dateFromThingProperty: input({type: 'string', acceptsNull: true}),
+    artistContribsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    artistContribsArtistProperty: input({type: 'string', acceptsNull: true}),
+    artTagsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    referencedArtworksFromThingProperty: input({type: 'string', acceptsNull: true}),
+  },
+
+  outputs: ['#constitutedArtwork'],
+
+  steps: () => [
+    {
+      dependencies: [
+        input.myself(),
+        input('thingProperty'),
+        input('dimensionsFromThingProperty'),
+        input('fileExtensionFromThingProperty'),
+        input('dateFromThingProperty'),
+        input('artistContribsFromThingProperty'),
+        input('artistContribsArtistProperty'),
+        input('artTagsFromThingProperty'),
+        input('referencedArtworksFromThingProperty'),
+      ],
+
+      compute: (continuation, {
+        [input.myself()]: myself,
+        [input('thingProperty')]: thingProperty,
+        [input('dimensionsFromThingProperty')]: dimensionsFromThingProperty,
+        [input('fileExtensionFromThingProperty')]: fileExtensionFromThingProperty,
+        [input('dateFromThingProperty')]: dateFromThingProperty,
+        [input('artistContribsFromThingProperty')]: artistContribsFromThingProperty,
+        [input('artistContribsArtistProperty')]: artistContribsArtistProperty,
+        [input('artTagsFromThingProperty')]: artTagsFromThingProperty,
+        [input('referencedArtworksFromThingProperty')]: referencedArtworksFromThingProperty,
+      }) => continuation({
+        ['#constitutedArtwork']:
+          Object.assign(new thingConstructors.Artwork, {
+            thing: myself,
+            thingProperty,
+            dimensionsFromThingProperty,
+            fileExtensionFromThingProperty,
+            artistContribsFromThingProperty,
+            artistContribsArtistProperty,
+            artTagsFromThingProperty,
+            dateFromThingProperty,
+            referencedArtworksFromThingProperty,
+          }),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/withContentNodes.js b/src/data/composite/wiki-data/withContentNodes.js
new file mode 100644
index 00000000..d014d43b
--- /dev/null
+++ b/src/data/composite/wiki-data/withContentNodes.js
@@ -0,0 +1,25 @@
+import {input, templateCompositeFrom} from '#composite';
+import {parseContentNodes} from '#replacer';
+
+export default templateCompositeFrom({
+  annotation: `withContentNodes`,
+
+  inputs: {
+    from: input({type: 'string', acceptsNull: false}),
+  },
+
+  outputs: ['#contentNodes'],
+
+  steps: () => [
+    {
+      dependencies: [input('from')],
+
+      compute: (continuation, {
+        [input('from')]: string,
+      }) => continuation({
+        ['#contentNodes']:
+          parseContentNodes(string),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/withContributionListSums.js b/src/data/composite/wiki-data/withContributionListSums.js
new file mode 100644
index 00000000..b4f36361
--- /dev/null
+++ b/src/data/composite/wiki-data/withContributionListSums.js
@@ -0,0 +1,95 @@
+// Gets the total duration and contribution count from a list of contributions,
+// respecting their `countInContributionTotals` and `countInDurationTotals`
+// flags.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {
+  withFilteredList,
+  withPropertiesFromList,
+  withPropertyFromList,
+  withSum,
+  withUniqueItemsOnly,
+} from '#composite/data';
+
+export default templateCompositeFrom({
+  annotation: `withContributionListSums`,
+
+  inputs: {
+    list: input({type: 'array'}),
+  },
+
+  outputs: [
+    '#contributionListCount',
+    '#contributionListDuration',
+  ],
+
+  steps: () => [
+    withPropertiesFromList({
+      list: input('list'),
+      properties: input.value([
+        'countInContributionTotals',
+        'countInDurationTotals',
+      ]),
+    }),
+
+    withFilteredList({
+      list: input('list'),
+      filter: '#list.countInContributionTotals',
+    }).outputs({
+      '#filteredList': '#contributionsForCounting',
+    }),
+
+    withFilteredList({
+      list: input('list'),
+      filter: '#list.countInDurationTotals',
+    }).outputs({
+      '#filteredList': '#contributionsForDuration',
+    }),
+
+    {
+      dependencies: ['#contributionsForCounting'],
+      compute: (continuation, {
+        ['#contributionsForCounting']: contributionsForCounting,
+      }) => continuation({
+        ['#count']:
+          contributionsForCounting.length,
+      }),
+    },
+
+    withPropertyFromList({
+      list: '#contributionsForDuration',
+      property: input.value('thing'),
+    }),
+
+    // Don't double-up the durations for a track where the artist has multiple
+    // contributions.
+    withUniqueItemsOnly({
+      list: '#contributionsForDuration.thing',
+    }),
+
+    withPropertyFromList({
+      list: '#contributionsForDuration.thing',
+      property: input.value('duration'),
+    }).outputs({
+      '#contributionsForDuration.thing.duration': '#durationValues',
+    }),
+
+    withSum({
+      values: '#durationValues',
+    }).outputs({
+      '#sum': '#duration',
+    }),
+
+    {
+      dependencies: ['#count', '#duration'],
+      compute: (continuation, {
+        ['#count']: count,
+        ['#duration']: duration,
+      }) => continuation({
+        ['#contributionListCount']: count,
+        ['#contributionListDuration']: duration,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/withCoverArtDate.js b/src/data/composite/wiki-data/withCoverArtDate.js
new file mode 100644
index 00000000..a114d5ff
--- /dev/null
+++ b/src/data/composite/wiki-data/withCoverArtDate.js
@@ -0,0 +1,51 @@
+import {input, templateCompositeFrom} from '#composite';
+import {isDate} from '#validators';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+import withResolvedContribs from './withResolvedContribs.js';
+
+export default templateCompositeFrom({
+  annotation: `withCoverArtDate`,
+
+  inputs: {
+    from: input({
+      validate: isDate,
+      defaultDependency: 'coverArtDate',
+      acceptsNull: true,
+    }),
+  },
+
+  outputs: ['#coverArtDate'],
+
+  steps: () => [
+    withResolvedContribs({
+      from: 'coverArtistContribs',
+      date: input.value(null),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#resolvedContribs',
+      mode: input.value('empty'),
+      output: input.value({'#coverArtDate': null}),
+    }),
+
+    {
+      dependencies: [input('from')],
+      compute: (continuation, {
+        [input('from')]: from,
+      }) =>
+        (from
+          ? continuation.raiseOutput({'#coverArtDate': from})
+          : continuation()),
+    },
+
+    {
+      dependencies: ['date'],
+      compute: (continuation, {date}) =>
+        (date
+          ? continuation({'#coverArtDate': date})
+          : continuation({'#coverArtDate': null})),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/withDirectory.js b/src/data/composite/wiki-data/withDirectory.js
new file mode 100644
index 00000000..f3bedf2e
--- /dev/null
+++ b/src/data/composite/wiki-data/withDirectory.js
@@ -0,0 +1,62 @@
+// Select a directory, either using a manually specified directory, or
+// computing it from a name. By default these values are the current thing's
+// 'directory' and 'name' properties, so it can be used without any options
+// to get the current thing's effective directory (assuming no custom rules).
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {isDirectory, isName} from '#validators';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+import withSimpleDirectory from './helpers/withSimpleDirectory.js';
+
+export default templateCompositeFrom({
+  annotation: `withDirectory`,
+
+  inputs: {
+    directory: input({
+      validate: isDirectory,
+      defaultDependency: 'directory',
+      acceptsNull: true,
+    }),
+
+    name: input({
+      validate: isName,
+      defaultDependency: 'name',
+      acceptsNull: true,
+    }),
+
+    suffix: input({
+      validate: isDirectory,
+      defaultValue: null,
+    }),
+  },
+
+  outputs: ['#directory'],
+
+  steps: () => [
+    withSimpleDirectory({
+      directory: input('directory'),
+      name: input('name'),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#directory',
+      output: input.value({['#directory']: null}),
+    }),
+
+    {
+      dependencies: ['#directory', input('suffix')],
+      compute: (continuation, {
+        ['#directory']: directory,
+        [input('suffix')]: suffix,
+      }) => continuation({
+        ['#directory']:
+          (suffix
+            ? directory + '-' + suffix
+            : directory),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/withParsedCommentaryEntries.js b/src/data/composite/wiki-data/withParsedCommentaryEntries.js
deleted file mode 100644
index f0404a5d..00000000
--- a/src/data/composite/wiki-data/withParsedCommentaryEntries.js
+++ /dev/null
@@ -1,179 +0,0 @@
-import {input, templateCompositeFrom} from '#composite';
-import find from '#find';
-import {stitchArrays} from '#sugar';
-import {isCommentary} from '#validators';
-import {commentaryRegexCaseSensitive} from '#wiki-data';
-
-import {
-  fillMissingListItems,
-  withFlattenedList,
-  withPropertiesFromList,
-  withUnflattenedList,
-} from '#composite/data';
-
-import withResolvedReferenceList from './withResolvedReferenceList.js';
-
-export default templateCompositeFrom({
-  annotation: `withParsedCommentaryEntries`,
-
-  inputs: {
-    from: input({validate: isCommentary}),
-  },
-
-  outputs: ['#parsedCommentaryEntries'],
-
-  steps: () => [
-    {
-      dependencies: [input('from')],
-
-      compute: (continuation, {
-        [input('from')]: commentaryText,
-      }) => continuation({
-        ['#rawMatches']:
-          Array.from(commentaryText.matchAll(commentaryRegexCaseSensitive)),
-      }),
-    },
-
-    withPropertiesFromList({
-      list: '#rawMatches',
-      properties: input.value([
-        '0', // The entire match as a string.
-        'groups',
-        'index',
-      ]),
-    }).outputs({
-      '#rawMatches.0': '#rawMatches.text',
-      '#rawMatches.groups': '#rawMatches.groups',
-      '#rawMatches.index': '#rawMatches.startIndex',
-    }),
-
-    {
-      dependencies: [
-        '#rawMatches.text',
-        '#rawMatches.startIndex',
-      ],
-
-      compute: (continuation, {
-        ['#rawMatches.text']: text,
-        ['#rawMatches.startIndex']: startIndex,
-      }) => continuation({
-        ['#rawMatches.endIndex']:
-          stitchArrays({text, startIndex})
-            .map(({text, startIndex}) => startIndex + text.length),
-      }),
-    },
-
-    {
-      dependencies: [
-        input('from'),
-        '#rawMatches.startIndex',
-        '#rawMatches.endIndex',
-      ],
-
-      compute: (continuation, {
-        [input('from')]: commentaryText,
-        ['#rawMatches.startIndex']: startIndex,
-        ['#rawMatches.endIndex']: endIndex,
-      }) => continuation({
-        ['#entries.body']:
-          stitchArrays({startIndex, endIndex})
-            .map(({endIndex}, index, stitched) =>
-              (index === stitched.length - 1
-                ? commentaryText.slice(endIndex)
-                : commentaryText.slice(
-                    endIndex,
-                    stitched[index + 1].startIndex)))
-            .map(body => body.trim()),
-      }),
-    },
-
-    withPropertiesFromList({
-      list: '#rawMatches.groups',
-      prefix: input.value('#entries'),
-      properties: input.value([
-        'artistReferences',
-        'artistDisplayText',
-        'annotation',
-        'date',
-      ]),
-    }),
-
-    // The artistReferences group will always have a value, since it's required
-    // for the line to match in the first place.
-
-    {
-      dependencies: ['#entries.artistReferences'],
-      compute: (continuation, {
-        ['#entries.artistReferences']: artistReferenceTexts,
-      }) => continuation({
-        ['#entries.artistReferences']:
-          artistReferenceTexts
-            .map(text => text.split(',').map(ref => ref.trim())),
-      }),
-    },
-
-    withFlattenedList({
-      list: '#entries.artistReferences',
-    }),
-
-    withResolvedReferenceList({
-      list: '#flattenedList',
-      data: 'artistData',
-      find: input.value(find.artist),
-      notFoundMode: input.value('null'),
-    }),
-
-    withUnflattenedList({
-      list: '#resolvedReferenceList',
-    }).outputs({
-      '#unflattenedList': '#entries.artists',
-    }),
-
-    fillMissingListItems({
-      list: '#entries.artistDisplayText',
-      fill: input.value(null),
-    }),
-
-    fillMissingListItems({
-      list: '#entries.annotation',
-      fill: input.value(null),
-    }),
-
-    {
-      dependencies: ['#entries.date'],
-      compute: (continuation, {
-        ['#entries.date']: date,
-      }) => continuation({
-        ['#entries.date']:
-          date.map(date => date ? new Date(date) : null),
-      }),
-    },
-
-    {
-      dependencies: [
-        '#entries.artists',
-        '#entries.artistDisplayText',
-        '#entries.annotation',
-        '#entries.date',
-        '#entries.body',
-      ],
-
-      compute: (continuation, {
-        ['#entries.artists']: artists,
-        ['#entries.artistDisplayText']: artistDisplayText,
-        ['#entries.annotation']: annotation,
-        ['#entries.date']: date,
-        ['#entries.body']: body,
-      }) => continuation({
-        ['#parsedCommentaryEntries']:
-          stitchArrays({
-            artists,
-            artistDisplayText,
-            annotation,
-            date,
-            body,
-          }),
-      }),
-    },
-  ],
-});
diff --git a/src/data/composite/wiki-data/withRecontextualizedContributionList.js b/src/data/composite/wiki-data/withRecontextualizedContributionList.js
new file mode 100644
index 00000000..bcc6e486
--- /dev/null
+++ b/src/data/composite/wiki-data/withRecontextualizedContributionList.js
@@ -0,0 +1,100 @@
+// Clones all the contributions in a list, with thing and thingProperty both
+// updated to match the current thing. Overwrites the provided dependency.
+// Optionally updates artistProperty as well. Doesn't do anything if
+// the provided dependency is null.
+//
+// See also:
+//  - withRedatedContributionList
+//
+
+import {input, templateCompositeFrom} from '#composite';
+import {isStringNonEmpty} from '#validators';
+
+import {withClonedThings} from '#composite/wiki-data';
+
+export default templateCompositeFrom({
+  annotation: `withRecontextualizedContributionList`,
+
+  inputs: {
+    list: input.staticDependency({
+      type: 'array',
+      acceptsNull: true,
+    }),
+
+    artistProperty: input({
+      validate: isStringNonEmpty,
+      defaultValue: null,
+    }),
+  },
+
+  outputs: ({
+    [input.staticDependency('list')]: list,
+  }) => [list],
+
+  steps: () => [
+    // TODO: Is raiseOutputWithoutDependency workable here?
+    // Is it true that not specifying any output wouldn't overwrite
+    // the provided dependency?
+    {
+      dependencies: [
+        input.staticDependency('list'),
+        input('list'),
+      ],
+
+      compute: (continuation, {
+        [input.staticDependency('list')]: dependency,
+        [input('list')]: list,
+      }) =>
+        (list
+          ? continuation()
+          : continuation.raiseOutput({
+              [dependency]: list,
+            })),
+    },
+
+    {
+      dependencies: [
+        input.myself(),
+        input.thisProperty(),
+        input('artistProperty'),
+      ],
+
+      compute: (continuation, {
+        [input.myself()]: myself,
+        [input.thisProperty()]: thisProperty,
+        [input('artistProperty')]: artistProperty,
+      }) => continuation({
+        ['#assignment']:
+          Object.assign(
+            {thing: myself},
+            {thingProperty: thisProperty},
+
+            (artistProperty
+              ? {artistProperty}
+              : {})),
+      }),
+    },
+
+    withClonedThings({
+      things: input('list'),
+      assign: '#assignment',
+    }).outputs({
+      '#clonedThings': '#newContributions',
+    }),
+
+    {
+      dependencies: [
+        input.staticDependency('list'),
+        '#newContributions',
+      ],
+
+      compute: (continuation, {
+        [input.staticDependency('list')]: listDependency,
+        ['#newContributions']: newContributions,
+      }) => continuation({
+        [listDependency]:
+          newContributions,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/withRedatedContributionList.js b/src/data/composite/wiki-data/withRedatedContributionList.js
new file mode 100644
index 00000000..12f3e16b
--- /dev/null
+++ b/src/data/composite/wiki-data/withRedatedContributionList.js
@@ -0,0 +1,127 @@
+// Clones all the contributions in a list, with date updated to the provided
+// value. Overwrites the provided dependency. Doesn't do anything if the
+// provided dependency is null, or the provided date is null.
+//
+// If 'override' is true (the default), then so long as the provided date has
+// a value at all, it's always written onto the (cloned) contributions.
+//
+// If 'override' is false, and any of the contributions were already dated,
+// those will keep their existing dates.
+//
+// See also:
+//  - withRecontextualizedContributionList
+//
+
+import {input, templateCompositeFrom} from '#composite';
+import {isDate} from '#validators';
+
+import {withMappedList, withPropertyFromList} from '#composite/data';
+import {withClonedThings} from '#composite/wiki-data';
+
+export default templateCompositeFrom({
+  annotation: `withRedatedContributionList`,
+
+  inputs: {
+    list: input.staticDependency({
+      type: 'array',
+      acceptsNull: true,
+    }),
+
+    date: input({
+      validate: isDate,
+      acceptsNull: true,
+    }),
+
+    override: input({
+      type: 'boolean',
+      defaultValue: true,
+    }),
+  },
+
+  outputs: ({
+    [input.staticDependency('list')]: list,
+  }) => [list],
+
+  steps: () => [
+    // TODO: Is raiseOutputWithoutDependency workable here?
+    // Is it true that not specifying any output wouldn't overwrite
+    // the provided dependency?
+    {
+      dependencies: [
+        input.staticDependency('list'),
+        input('list'),
+        input('date'),
+      ],
+
+      compute: (continuation, {
+        [input.staticDependency('list')]: dependency,
+        [input('list')]: list,
+        [input('date')]: date,
+      }) =>
+        (list && date
+          ? continuation()
+          : continuation.raiseOutput({
+              [dependency]: list,
+            })),
+    },
+
+    withPropertyFromList({
+      list: input('list'),
+      property: input.value('date'),
+    }).outputs({
+      '#list.date': '#existingDates',
+    }),
+
+    {
+      dependencies: [
+        input('date'),
+        input('override'),
+        '#existingDates',
+      ],
+
+      compute: (continuation, {
+        [input('date')]: date,
+        [input('override')]: override,
+        '#existingDates': existingDates,
+      }) => continuation({
+        ['#assignmentMap']:
+          // TODO: Should be mapping over withIndicesFromList
+          (_, index) =>
+            (!override && existingDates[index]
+              ? {date: existingDates[index]}
+           : date
+              ? {date}
+              : {}),
+      }),
+    },
+
+    withMappedList({
+      list: input('list'),
+      map: '#assignmentMap',
+    }).outputs({
+      '#mappedList': '#assignment',
+    }),
+
+    withClonedThings({
+      things: input('list'),
+      assignEach: '#assignment',
+    }).outputs({
+      '#clonedThings': '#newContributions',
+    }),
+
+    {
+      dependencies: [
+        input.staticDependency('list'),
+        '#newContributions',
+      ],
+
+      compute: (continuation, {
+        [input.staticDependency('list')]: listDependency,
+        ['#newContributions']: newContributions,
+      }) => continuation({
+        [listDependency]:
+          newContributions,
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/wiki-data/withResolvedAnnotatedReferenceList.js b/src/data/composite/wiki-data/withResolvedAnnotatedReferenceList.js
new file mode 100644
index 00000000..9cc52f29
--- /dev/null
+++ b/src/data/composite/wiki-data/withResolvedAnnotatedReferenceList.js
@@ -0,0 +1,100 @@
+import {input, templateCompositeFrom} from '#composite';
+import {stitchArrays} from '#sugar';
+import {isObject, validateArrayItems} from '#validators';
+
+import {withPropertyFromList} from '#composite/data';
+
+import {raiseOutputWithoutDependency, withAvailabilityFilter}
+  from '#composite/control-flow';
+
+import inputSoupyFind from './inputSoupyFind.js';
+import inputNotFoundMode from './inputNotFoundMode.js';
+import inputWikiData from './inputWikiData.js';
+import raiseResolvedReferenceList from './raiseResolvedReferenceList.js';
+import withResolvedReferenceList from './withResolvedReferenceList.js';
+
+export default templateCompositeFrom({
+  annotation: `withResolvedAnnotatedReferenceList`,
+
+  inputs: {
+    list: input({
+      validate: validateArrayItems(isObject),
+      acceptsNull: true,
+    }),
+
+    reference: input({type: 'string', defaultValue: 'reference'}),
+    annotation: input({type: 'string', defaultValue: 'annotation'}),
+    thing: input({type: 'string', defaultValue: 'thing'}),
+
+    data: inputWikiData({allowMixedTypes: true}),
+    find: inputSoupyFind(),
+
+    notFoundMode: inputNotFoundMode(),
+  },
+
+  outputs: ['#resolvedAnnotatedReferenceList'],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: input('list'),
+      mode: input.value('empty'),
+      output: input.value({
+        ['#resolvedAnnotatedReferenceList']: [],
+      }),
+    }),
+
+    withPropertyFromList({
+      list: input('list'),
+      property: input('reference'),
+    }).outputs({
+      ['#values']: '#references',
+    }),
+
+    withPropertyFromList({
+      list: input('list'),
+      property: input('annotation'),
+    }).outputs({
+      ['#values']: '#annotations',
+    }),
+
+    withResolvedReferenceList({
+      list: '#references',
+      data: input('data'),
+      find: input('find'),
+      notFoundMode: input.value('null'),
+    }),
+
+    {
+      dependencies: [
+        input('thing'),
+        input('annotation'),
+        '#resolvedReferenceList',
+        '#annotations',
+      ],
+
+      compute: (continuation, {
+        [input('thing')]: thingProperty,
+        [input('annotation')]: annotationProperty,
+        ['#resolvedReferenceList']: things,
+        ['#annotations']: annotations,
+      }) => continuation({
+        ['#matches']:
+          stitchArrays({
+            [thingProperty]: things,
+            [annotationProperty]: annotations,
+          }),
+      }),
+    },
+
+    withAvailabilityFilter({
+      from: '#resolvedReferenceList',
+    }),
+
+    raiseResolvedReferenceList({
+      notFoundMode: input('notFoundMode'),
+      results: '#matches',
+      filter: '#availabilityFilter',
+      outputs: input.value('#resolvedAnnotatedReferenceList'),
+    }),
+  ],
+})
diff --git a/src/data/composite/wiki-data/withResolvedContribs.js b/src/data/composite/wiki-data/withResolvedContribs.js
index 77b0f96d..838c991f 100644
--- a/src/data/composite/wiki-data/withResolvedContribs.js
+++ b/src/data/composite/wiki-data/withResolvedContribs.js
@@ -1,22 +1,20 @@
 // Resolves the contribsByRef contained in the provided dependency,
 // providing (named by the second argument) the result. "Resolving"
-// means mapping the "who" reference of each contribution to an artist
-// object, and filtering out those whose "who" doesn't match any artist.
+// means mapping the artist reference of each contribution to an artist
+// object, and filtering out those whose artist reference doesn't match
+// any artist.
 
 import {input, templateCompositeFrom} from '#composite';
-import find from '#find';
 import {filterMultipleArrays, stitchArrays} from '#sugar';
-import {is, isContributionList} from '#validators';
+import thingConstructors from '#things';
+import {isContributionList, isDate, isStringNonEmpty} from '#validators';
 
-import {
-  raiseOutputWithoutDependency,
-} from '#composite/control-flow';
+import {raiseOutputWithoutDependency, withAvailabilityFilter}
+  from '#composite/control-flow';
+import {withPropertyFromList, withPropertiesFromList} from '#composite/data';
 
-import {
-  withPropertiesFromList,
-} from '#composite/data';
-
-import withResolvedReferenceList from './withResolvedReferenceList.js';
+import inputNotFoundMode from './inputNotFoundMode.js';
+import raiseResolvedReferenceList from './raiseResolvedReferenceList.js';
 
 export default templateCompositeFrom({
   annotation: `withResolvedContribs`,
@@ -27,9 +25,21 @@ export default templateCompositeFrom({
       acceptsNull: true,
     }),
 
-    notFoundMode: input({
-      validate: is('exit', 'filter', 'null'),
-      defaultValue: 'null',
+    date: input({
+      validate: isDate,
+      acceptsNull: true,
+    }),
+
+    notFoundMode: inputNotFoundMode(),
+
+    thingProperty: input({
+      validate: isStringNonEmpty,
+      defaultValue: null,
+    }),
+
+    artistProperty: input({
+      validate: isStringNonEmpty,
+      defaultValue: null,
     }),
   },
 
@@ -44,33 +54,103 @@ export default templateCompositeFrom({
       }),
     }),
 
+    {
+      dependencies: [
+        input('thingProperty'),
+        input.staticDependency('from'),
+      ],
+
+      compute: (continuation, {
+        [input('thingProperty')]: thingProperty,
+        [input.staticDependency('from')]: fromDependency,
+      }) => continuation({
+        ['#thingProperty']:
+          (thingProperty
+            ? thingProperty
+         : !fromDependency?.startsWith('#')
+            ? fromDependency
+            : null),
+      }),
+    },
+
     withPropertiesFromList({
       list: input('from'),
-      properties: input.value(['who', 'what']),
+      properties: input.value(['artist', 'annotation']),
       prefix: input.value('#contribs'),
     }),
 
-    withResolvedReferenceList({
-      list: '#contribs.who',
-      data: 'artistData',
-      find: input.value(find.artist),
-      notFoundMode: input('notFoundMode'),
-    }).outputs({
-      ['#resolvedReferenceList']: '#contribs.who',
-    }),
-
     {
-      dependencies: ['#contribs.who', '#contribs.what'],
+      dependencies: [
+        '#contribs.artist',
+        '#contribs.annotation',
+        input('date'),
+      ],
 
       compute(continuation, {
-        ['#contribs.who']: who,
-        ['#contribs.what']: what,
+        ['#contribs.artist']: artist,
+        ['#contribs.annotation']: annotation,
+        [input('date')]: date,
       }) {
-        filterMultipleArrays(who, what, (who, _what) => who);
+        filterMultipleArrays(artist, annotation, (artist, _annotation) => artist);
+
         return continuation({
-          ['#resolvedContribs']: stitchArrays({who, what}),
+          ['#details']:
+            stitchArrays({artist, annotation})
+              .map(details => ({
+                ...details,
+                date: date ?? null,
+              })),
         });
       },
     },
+
+    {
+      dependencies: [
+        '#details',
+        '#thingProperty',
+        input('artistProperty'),
+        input.myself(),
+        'find',
+      ],
+
+      compute: (continuation, {
+        ['#details']: details,
+        ['#thingProperty']: thingProperty,
+        [input('artistProperty')]: artistProperty,
+        [input.myself()]: myself,
+        ['find']: find,
+      }) => continuation({
+        ['#contributions']:
+          details.map(details => {
+            const contrib = new thingConstructors.Contribution();
+
+            Object.assign(contrib, {
+              ...details,
+              thing: myself,
+              thingProperty: thingProperty,
+              artistProperty: artistProperty,
+              find: find,
+            });
+
+            return contrib;
+          }),
+      }),
+    },
+
+    withPropertyFromList({
+      list: '#contributions',
+      property: input.value('artist'),
+    }),
+
+    withAvailabilityFilter({
+      from: '#contributions.artist',
+    }),
+
+    raiseResolvedReferenceList({
+      notFoundMode: input('notFoundMode'),
+      results: '#contributions',
+      filter: '#availabilityFilter',
+      outputs: input.value('#resolvedContribs'),
+    }),
   ],
 });
diff --git a/src/data/composite/wiki-data/withResolvedReference.js b/src/data/composite/wiki-data/withResolvedReference.js
index ea71707e..6f422194 100644
--- a/src/data/composite/wiki-data/withResolvedReference.js
+++ b/src/data/composite/wiki-data/withResolvedReference.js
@@ -1,16 +1,14 @@
 // Resolves a reference by using the provided find function to match it
-// within the provided thingData dependency. This will early exit if the
-// data dependency is null. Otherwise, the data object is provided on the
-// output dependency, or null, if the reference doesn't match anything or
+// within the provided thingData dependency. The data object is provided on
+// the output dependency, or null, if the reference doesn't match anything or
 // itself was null to begin with.
 
 import {input, templateCompositeFrom} from '#composite';
 
-import {
-  exitWithoutDependency,
-  raiseOutputWithoutDependency,
-} from '#composite/control-flow';
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
 
+import gobbleSoupyFind from './gobbleSoupyFind.js';
+import inputSoupyFind from './inputSoupyFind.js';
 import inputWikiData from './inputWikiData.js';
 
 export default templateCompositeFrom({
@@ -20,7 +18,7 @@ export default templateCompositeFrom({
     ref: input({type: 'string', acceptsNull: true}),
 
     data: inputWikiData({allowMixedTypes: false}),
-    find: input({type: 'function'}),
+    find: inputSoupyFind(),
   },
 
   outputs: ['#resolvedReference'],
@@ -33,24 +31,26 @@ export default templateCompositeFrom({
       }),
     }),
 
-    exitWithoutDependency({
-      dependency: input('data'),
+    gobbleSoupyFind({
+      find: input('find'),
     }),
 
     {
       dependencies: [
         input('ref'),
         input('data'),
-        input('find'),
+        '#find',
       ],
 
       compute: (continuation, {
         [input('ref')]: ref,
         [input('data')]: data,
-        [input('find')]: findFunction,
+        ['#find']: findFunction,
       }) => continuation({
         ['#resolvedReference']:
-          findFunction(ref, data, {mode: 'quiet'}) ?? null,
+          (data
+            ? findFunction(ref, data, {mode: 'quiet'}) ?? null
+            : findFunction(ref, {mode: 'quiet'}) ?? null),
       }),
     },
   ],
diff --git a/src/data/composite/wiki-data/withResolvedReferenceList.js b/src/data/composite/wiki-data/withResolvedReferenceList.js
index 1d39e5b2..9dc960dd 100644
--- a/src/data/composite/wiki-data/withResolvedReferenceList.js
+++ b/src/data/composite/wiki-data/withResolvedReferenceList.js
@@ -1,18 +1,20 @@
 // Resolves a list of references, with each reference matched with provided
-// data in the same way as withResolvedReference. This will early exit if the
-// data dependency is null (even if the reference list is empty). By default
-// it will filter out references which don't match, but this can be changed
-// to early exit ({notFoundMode: 'exit'}) or leave null in place ('null').
+// data in the same way as withResolvedReference. By default it will filter
+// out references which don't match, but this can be changed to early exit
+// ({notFoundMode: 'exit'}) or leave null in place ('null').
 
 import {input, templateCompositeFrom} from '#composite';
-import {is, isString, validateArrayItems} from '#validators';
+import {isString, validateArrayItems} from '#validators';
 
-import {
-  exitWithoutDependency,
-  raiseOutputWithoutDependency,
-} from '#composite/control-flow';
+import {raiseOutputWithoutDependency, withAvailabilityFilter}
+  from '#composite/control-flow';
+import {withMappedList} from '#composite/data';
 
+import gobbleSoupyFind from './gobbleSoupyFind.js';
+import inputNotFoundMode from './inputNotFoundMode.js';
+import inputSoupyFind from './inputSoupyFind.js';
 import inputWikiData from './inputWikiData.js';
+import raiseResolvedReferenceList from './raiseResolvedReferenceList.js';
 
 export default templateCompositeFrom({
   annotation: `withResolvedReferenceList`,
@@ -23,23 +25,15 @@ export default templateCompositeFrom({
       acceptsNull: true,
     }),
 
-    data: inputWikiData({allowMixedTypes: false}),
-    find: input({type: 'function'}),
+    data: inputWikiData({allowMixedTypes: true}),
+    find: inputSoupyFind(),
 
-    notFoundMode: input({
-      validate: is('exit', 'filter', 'null'),
-      defaultValue: 'filter',
-    }),
+    notFoundMode: inputNotFoundMode(),
   },
 
   outputs: ['#resolvedReferenceList'],
 
   steps: () => [
-    exitWithoutDependency({
-      dependency: input('data'),
-      value: input.value([]),
-    }),
-
     raiseOutputWithoutDependency({
       dependency: input('list'),
       mode: input.value('empty'),
@@ -48,54 +42,39 @@ export default templateCompositeFrom({
       }),
     }),
 
+    gobbleSoupyFind({
+      find: input('find'),
+    }),
+
     {
-      dependencies: [input('list'), input('data'), input('find')],
+      dependencies: [input('data'), '#find'],
       compute: (continuation, {
-        [input('list')]: list,
         [input('data')]: data,
-        [input('find')]: findFunction,
-      }) =>
-        continuation({
-          '#matches': list.map(ref => findFunction(ref, data, {mode: 'quiet'})),
-        }),
-    },
-
-    {
-      dependencies: ['#matches'],
-      compute: (continuation, {'#matches': matches}) =>
-        (matches.every(match => match)
-          ? continuation.raiseOutput({
-              ['#resolvedReferenceList']: matches,
-            })
-          : continuation()),
+        ['#find']: findFunction,
+      }) => continuation({
+        ['#map']:
+          (data
+            ? ref => findFunction(ref, data, {mode: 'quiet'})
+            : ref => findFunction(ref, {mode: 'quiet'})),
+      }),
     },
 
-    {
-      dependencies: ['#matches', input('notFoundMode')],
-      compute(continuation, {
-        ['#matches']: matches,
-        [input('notFoundMode')]: notFoundMode,
-      }) {
-        switch (notFoundMode) {
-          case 'exit':
-            return continuation.exit([]);
-
-          case 'filter':
-            return continuation.raiseOutput({
-              ['#resolvedReferenceList']:
-                matches.filter(match => match),
-            });
+    withMappedList({
+      list: input('list'),
+      map: '#map',
+    }).outputs({
+      '#mappedList': '#matches',
+    }),
 
-          case 'null':
-            return continuation.raiseOutput({
-              ['#resolvedReferenceList']:
-                matches.map(match => match ?? null),
-            });
+    withAvailabilityFilter({
+      from: '#matches',
+    }),
 
-          default:
-            throw new TypeError(`Expected notFoundMode to be exit, filter, or null`);
-        }
-      },
-    },
+    raiseResolvedReferenceList({
+      notFoundMode: input('notFoundMode'),
+      results: '#matches',
+      filter: '#availabilityFilter',
+      outputs: input.value('#resolvedReferenceList'),
+    }),
   ],
 });
diff --git a/src/data/composite/wiki-data/withReverseContributionList.js b/src/data/composite/wiki-data/withReverseContributionList.js
deleted file mode 100644
index eccb58b7..00000000
--- a/src/data/composite/wiki-data/withReverseContributionList.js
+++ /dev/null
@@ -1,83 +0,0 @@
-// Analogous implementation for withReverseReferenceList, for contributions.
-// This is all duplicate code and both should be ported to the same underlying
-// data form later on.
-//
-// This implementation uses a global cache (via WeakMap) to attempt to speed
-// up subsequent similar accesses.
-//
-// This has absolutely not been rigorously tested with altering properties of
-// data objects in a wiki data array which is reused. If a new wiki data array
-// is used, a fresh cache will always be created.
-
-import {input, templateCompositeFrom} from '#composite';
-
-import {exitWithoutDependency} from '#composite/control-flow';
-
-import inputWikiData from './inputWikiData.js';
-
-// Mapping of reference list property to WeakMap.
-// Each WeakMap maps a wiki data array to another weak map,
-// which in turn maps each referenced thing to an array of
-// things referencing it.
-const caches = new Map();
-
-export default templateCompositeFrom({
-  annotation: `withReverseContributionList`,
-
-  inputs: {
-    data: inputWikiData({allowMixedTypes: false}),
-    list: input({type: 'string'}),
-  },
-
-  outputs: ['#reverseContributionList'],
-
-  steps: () => [
-    exitWithoutDependency({
-      dependency: input('data'),
-      value: input.value([]),
-      mode: input.value('empty'),
-    }),
-
-    {
-      dependencies: [input.myself(), input('data'), input('list')],
-
-      compute: (continuation, {
-        [input.myself()]: myself,
-        [input('data')]: data,
-        [input('list')]: list,
-      }) => {
-        if (!caches.has(list)) {
-          caches.set(list, new WeakMap());
-        }
-
-        const cache = caches.get(list);
-
-        if (!cache.has(data)) {
-          const cacheRecord = new WeakMap();
-
-          for (const referencingThing of data) {
-            const referenceList = referencingThing[list];
-
-            // Destructuring {who} is the only unique part of the
-            // withReverseContributionList implementation, compared to
-            // withReverseReferneceList.
-            for (const {who: referencedThing} of referenceList) {
-              if (cacheRecord.has(referencedThing)) {
-                cacheRecord.get(referencedThing).push(referencingThing);
-              } else {
-                cacheRecord.set(referencedThing, [referencingThing]);
-              }
-            }
-          }
-
-          cache.set(data, cacheRecord);
-        }
-
-        return continuation({
-          ['#reverseContributionList']:
-            cache.get(data).get(myself) ?? [],
-        });
-      },
-    },
-  ],
-});
diff --git a/src/data/composite/wiki-data/withReverseReferenceList.js b/src/data/composite/wiki-data/withReverseReferenceList.js
index 2d7a421b..906f5bc5 100644
--- a/src/data/composite/wiki-data/withReverseReferenceList.js
+++ b/src/data/composite/wiki-data/withReverseReferenceList.js
@@ -1,81 +1,36 @@
 // Check out the info on reverseReferenceList!
 // This is its composable form.
-//
-// This implementation uses a global cache (via WeakMap) to attempt to speed
-// up subsequent similar accesses.
-//
-// This has absolutely not been rigorously tested with altering properties of
-// data objects in a wiki data array which is reused. If a new wiki data array
-// is used, a fresh cache will always be created.
-//
-// Note that this implementation is mirrored in withReverseContributionList,
-// so any changes should be reflected there (until these are combined).
 
 import {input, templateCompositeFrom} from '#composite';
 
-import {exitWithoutDependency} from '#composite/control-flow';
-
+import gobbleSoupyReverse from './gobbleSoupyReverse.js';
+import inputSoupyReverse from './inputSoupyReverse.js';
 import inputWikiData from './inputWikiData.js';
 
-// Mapping of reference list property to WeakMap.
-// Each WeakMap maps a wiki data array to another weak map,
-// which in turn maps each referenced thing to an array of
-// things referencing it.
-const caches = new Map();
+import withResolvedReverse from './helpers/withResolvedReverse.js';
 
 export default templateCompositeFrom({
   annotation: `withReverseReferenceList`,
 
   inputs: {
-    data: inputWikiData({allowMixedTypes: false}),
-    list: input({type: 'string'}),
+    data: inputWikiData({allowMixedTypes: true}),
+    reverse: inputSoupyReverse(),
   },
 
   outputs: ['#reverseReferenceList'],
 
   steps: () => [
-    exitWithoutDependency({
-      dependency: input('data'),
-      value: input.value([]),
-      mode: input.value('empty'),
+    gobbleSoupyReverse({
+      reverse: input('reverse'),
     }),
 
-    {
-      dependencies: [input.myself(), input('data'), input('list')],
-
-      compute: (continuation, {
-        [input.myself()]: myself,
-        [input('data')]: data,
-        [input('list')]: list,
-      }) => {
-        if (!caches.has(list)) {
-          caches.set(list, new WeakMap());
-        }
-
-        const cache = caches.get(list);
-
-        if (!cache.has(data)) {
-          const cacheRecord = new WeakMap();
+    // TODO: Check that the reverse spec returns a list.
 
-          for (const referencingThing of data) {
-            const referenceList = referencingThing[list];
-            for (const referencedThing of referenceList) {
-              if (cacheRecord.has(referencedThing)) {
-                cacheRecord.get(referencedThing).push(referencingThing);
-              } else {
-                cacheRecord.set(referencedThing, [referencingThing]);
-              }
-            }
-          }
-
-          cache.set(data, cacheRecord);
-        }
-
-        return continuation({
-          ['#reverseReferenceList']:
-            cache.get(data).get(myself) ?? [],
-        });
-      },
-    },
+    withResolvedReverse({
+      data: input('data'),
+      reverse: '#reverse',
+    }).outputs({
+      '#resolvedReverse': '#reverseReferenceList',
+    }),
   ],
 });
diff --git a/src/data/composite/wiki-data/withUniqueReferencingThing.js b/src/data/composite/wiki-data/withUniqueReferencingThing.js
new file mode 100644
index 00000000..7c267038
--- /dev/null
+++ b/src/data/composite/wiki-data/withUniqueReferencingThing.js
@@ -0,0 +1,36 @@
+// Like withReverseReferenceList, but this is specifically for special "unique"
+// references, meaning this thing is referenced by exactly one or zero things
+// in the data list.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import gobbleSoupyReverse from './gobbleSoupyReverse.js';
+import inputSoupyReverse from './inputSoupyReverse.js';
+import inputWikiData from './inputWikiData.js';
+
+import withResolvedReverse from './helpers/withResolvedReverse.js';
+
+export default templateCompositeFrom({
+  annotation: `withUniqueReferencingThing`,
+
+  inputs: {
+    data: inputWikiData({allowMixedTypes: true}),
+    reverse: inputSoupyReverse(),
+  },
+
+  outputs: ['#uniqueReferencingThing'],
+
+  steps: () => [
+    gobbleSoupyReverse({
+      reverse: input('reverse'),
+    }),
+
+    withResolvedReverse({
+      data: input('data'),
+      reverse: '#reverse',
+      options: input.value({unique: true}),
+    }).outputs({
+      '#resolvedReverse': '#uniqueReferencingThing',
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-properties/additionalFiles.js b/src/data/composite/wiki-properties/additionalFiles.js
deleted file mode 100644
index 6760527a..00000000
--- a/src/data/composite/wiki-properties/additionalFiles.js
+++ /dev/null
@@ -1,30 +0,0 @@
-// This is a somewhat more involved data structure - it's for additional
-// or "bonus" files associated with albums or tracks (or anything else).
-// It's got this form:
-//
-//   [
-//     {title: 'Booklet', files: ['Booklet.pdf']},
-//     {
-//       title: 'Wallpaper',
-//       description: 'Cool Wallpaper!',
-//       files: ['1440x900.png', '1920x1080.png']
-//     },
-//     {title: 'Alternate Covers', description: null, files: [...]},
-//     ...
-//   ]
-//
-
-import {isAdditionalFileList} from '#validators';
-
-// TODO: Not templateCompositeFrom.
-
-export default function() {
-  return {
-    flags: {update: true, expose: true},
-    update: {validate: isAdditionalFileList},
-    expose: {
-      transform: (additionalFiles) =>
-        additionalFiles ?? [],
-    },
-  };
-}
diff --git a/src/data/composite/wiki-properties/additionalNameList.js b/src/data/composite/wiki-properties/additionalNameList.js
deleted file mode 100644
index c5971d4a..00000000
--- a/src/data/composite/wiki-properties/additionalNameList.js
+++ /dev/null
@@ -1,14 +0,0 @@
-// A list of additional names! These can be used for a variety of purposes,
-// e.g. providing extra searchable titles, localizations, romanizations or
-// original titles, and so on. Each item has a name and, optionally, a
-// descriptive annotation.
-
-import {isAdditionalNameList} from '#validators';
-
-export default function() {
-  return {
-    flags: {update: true, expose: true},
-    update: {validate: isAdditionalNameList},
-    expose: {transform: value => value ?? []},
-  };
-}
diff --git a/src/data/composite/wiki-properties/annotatedReferenceList.js b/src/data/composite/wiki-properties/annotatedReferenceList.js
new file mode 100644
index 00000000..8e6c96a1
--- /dev/null
+++ b/src/data/composite/wiki-properties/annotatedReferenceList.js
@@ -0,0 +1,64 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {
+  isContentString,
+  optional,
+  validateArrayItems,
+  validateProperties,
+  validateReference,
+} from '#validators';
+
+import {exposeDependency} from '#composite/control-flow';
+import {inputSoupyFind, inputWikiData, withResolvedAnnotatedReferenceList}
+  from '#composite/wiki-data';
+
+import {referenceListInputDescriptions, referenceListUpdateDescription}
+  from './helpers/reference-list-helpers.js';
+
+export default templateCompositeFrom({
+  annotation: `annotatedReferenceList`,
+
+  compose: false,
+
+  inputs: {
+    ...referenceListInputDescriptions(),
+
+    data: inputWikiData({allowMixedTypes: true}),
+    find: inputSoupyFind(),
+
+    reference: input.staticValue({type: 'string', defaultValue: 'reference'}),
+    annotation: input.staticValue({type: 'string', defaultValue: 'annotation'}),
+    thing: input.staticValue({type: 'string', defaultValue: 'thing'}),
+  },
+
+  update(staticInputs) {
+    const {
+      [input.staticValue('reference')]: referenceProperty,
+      [input.staticValue('annotation')]: annotationProperty,
+    } = staticInputs;
+
+    return referenceListUpdateDescription({
+      validateReferenceList: type =>
+        validateArrayItems(
+          validateProperties({
+            [referenceProperty]: validateReference(type),
+            [annotationProperty]: optional(isContentString),
+          })),
+    })(staticInputs);
+  },
+
+  steps: () => [
+    withResolvedAnnotatedReferenceList({
+      list: input.updateValue(),
+
+      reference: input('reference'),
+      annotation: input('annotation'),
+      thing: input('thing'),
+
+      data: input('data'),
+      find: input('find'),
+    }),
+
+    exposeDependency({dependency: '#resolvedAnnotatedReferenceList'}),
+  ],
+});
diff --git a/src/data/composite/wiki-properties/commentary.js b/src/data/composite/wiki-properties/commentary.js
deleted file mode 100644
index cd6b7ac4..00000000
--- a/src/data/composite/wiki-properties/commentary.js
+++ /dev/null
@@ -1,30 +0,0 @@
-// Artist commentary! Generally present on tracks and albums.
-
-import {input, templateCompositeFrom} from '#composite';
-import {isCommentary} from '#validators';
-
-import {exitWithoutDependency, exposeDependency}
-  from '#composite/control-flow';
-import {withParsedCommentaryEntries} from '#composite/wiki-data';
-
-export default templateCompositeFrom({
-  annotation: `commentary`,
-
-  compose: false,
-
-  steps: () => [
-    exitWithoutDependency({
-      dependency: input.updateValue({validate: isCommentary}),
-      mode: input.value('falsy'),
-      value: input.value(null),
-    }),
-
-    withParsedCommentaryEntries({
-      from: input.updateValue(),
-    }),
-
-    exposeDependency({
-      dependency: '#parsedCommentaryEntries',
-    }),
-  ],
-});
diff --git a/src/data/composite/wiki-properties/commentatorArtists.js b/src/data/composite/wiki-properties/commentatorArtists.js
index c5c14769..54d3e1a5 100644
--- a/src/data/composite/wiki-properties/commentatorArtists.js
+++ b/src/data/composite/wiki-properties/commentatorArtists.js
@@ -7,7 +7,6 @@ import {exitWithoutDependency, exposeDependency}
   from '#composite/control-flow';
 import {withFlattenedList, withPropertyFromList, withUniqueItemsOnly}
   from '#composite/data';
-import {withParsedCommentaryEntries} from '#composite/wiki-data';
 
 export default templateCompositeFrom({
   annotation: `commentatorArtists`,
@@ -21,19 +20,13 @@ export default templateCompositeFrom({
       value: input.value([]),
     }),
 
-    withParsedCommentaryEntries({
-      from: 'commentary',
-    }),
-
     withPropertyFromList({
-      list: '#parsedCommentaryEntries',
+      list: 'commentary',
       property: input.value('artists'),
-    }).outputs({
-      '#parsedCommentaryEntries.artists': '#artistLists',
     }),
 
     withFlattenedList({
-      list: '#artistLists',
+      list: '#commentary.artists',
     }).outputs({
       '#flattenedList': '#artists',
     }),
diff --git a/src/data/composite/wiki-properties/constitutibleArtwork.js b/src/data/composite/wiki-properties/constitutibleArtwork.js
new file mode 100644
index 00000000..48f4211a
--- /dev/null
+++ b/src/data/composite/wiki-properties/constitutibleArtwork.js
@@ -0,0 +1,70 @@
+// This composition does not actually inspect the values of any properties
+// specified, so it's not responsible for determining whether a constituted
+// artwork should exist at all.
+
+import {input, templateCompositeFrom} from '#composite';
+import {withEntries} from '#sugar';
+import Thing from '#thing';
+import {validateThing} from '#validators';
+
+import {exposeDependency, exposeUpdateValueOrContinue}
+  from '#composite/control-flow';
+import {withConstitutedArtwork} from '#composite/wiki-data';
+
+const template = templateCompositeFrom({
+  annotation: `constitutibleArtwork`,
+
+  compose: false,
+
+  inputs: {
+    thingProperty: input({type: 'string', acceptsNull: true}),
+    dimensionsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    fileExtensionFromThingProperty: input({type: 'string', acceptsNull: true}),
+    dateFromThingProperty: input({type: 'string', acceptsNull: true}),
+    artistContribsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    artistContribsArtistProperty: input({type: 'string', acceptsNull: true}),
+    artTagsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    referencedArtworksFromThingProperty: input({type: 'string', acceptsNull: true}),
+  },
+
+  steps: () => [
+    exposeUpdateValueOrContinue({
+      validate: input.value(
+        validateThing({
+          referenceType: 'artwork',
+        })),
+    }),
+
+    withConstitutedArtwork({
+      thingProperty: input('thingProperty'),
+      dimensionsFromThingProperty: input('dimensionsFromThingProperty'),
+      fileExtensionFromThingProperty: input('fileExtensionFromThingProperty'),
+      dateFromThingProperty: input('dateFromThingProperty'),
+      artistContribsFromThingProperty: input('artistContribsFromThingProperty'),
+      artistContribsArtistProperty: input('artistContribsArtistProperty'),
+      artTagsFromThingProperty: input('artTagsFromThingProperty'),
+      referencedArtworksFromThingProperty: input('referencedArtworksFromThingProperty'),
+    }),
+
+    exposeDependency({
+      dependency: '#constitutedArtwork',
+    }),
+  ],
+});
+
+template.fromYAMLFieldSpec = function(field) {
+  const {[Thing.yamlDocumentSpec]: documentSpec} = this;
+
+  const {provide} = documentSpec.fields[field].transform;
+
+  const inputs =
+    withEntries(provide, entries =>
+      entries.map(([property, value]) => [
+        property,
+        input.value(value),
+      ]));
+
+  return template(inputs);
+};
+
+export default template;
diff --git a/src/data/composite/wiki-properties/constitutibleArtworkList.js b/src/data/composite/wiki-properties/constitutibleArtworkList.js
new file mode 100644
index 00000000..dad3a957
--- /dev/null
+++ b/src/data/composite/wiki-properties/constitutibleArtworkList.js
@@ -0,0 +1,72 @@
+// This composition does not actually inspect the values of any properties
+// specified, so it's not responsible for determining whether a constituted
+// artwork should exist at all.
+
+import {input, templateCompositeFrom} from '#composite';
+import {withEntries} from '#sugar';
+import Thing from '#thing';
+import {validateWikiData} from '#validators';
+
+import {exposeUpdateValueOrContinue} from '#composite/control-flow';
+import {withConstitutedArtwork} from '#composite/wiki-data';
+
+const template = templateCompositeFrom({
+  annotation: `constitutibleArtworkList`,
+
+  compose: false,
+
+  inputs: {
+    thingProperty: input({type: 'string', acceptsNull: true}),
+    dimensionsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    fileExtensionFromThingProperty: input({type: 'string', acceptsNull: true}),
+    dateFromThingProperty: input({type: 'string', acceptsNull: true}),
+    artistContribsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    artistContribsArtistProperty: input({type: 'string', acceptsNull: true}),
+    artTagsFromThingProperty: input({type: 'string', acceptsNull: true}),
+    referencedArtworksFromThingProperty: input({type: 'string', acceptsNull: true}),
+  },
+
+  steps: () => [
+    exposeUpdateValueOrContinue({
+      validate: input.value(
+        validateWikiData({
+          referenceType: 'artwork',
+        })),
+    }),
+
+    withConstitutedArtwork({
+      thingProperty: input('thingProperty'),
+      dimensionsFromThingProperty: input('dimensionsFromThingProperty'),
+      fileExtensionFromThingProperty: input('fileExtensionFromThingProperty'),
+      dateFromThingProperty: input('dateFromThingProperty'),
+      artistContribsFromThingProperty: input('artistContribsFromThingProperty'),
+      artistContribsArtistProperty: input('artistContribsArtistProperty'),
+      artTagsFromThingProperty: input('artTagsFromThingProperty'),
+      referencedArtworksFromThingProperty: input('referencedArtworksFromThingProperty'),
+    }),
+
+    {
+      dependencies: ['#constitutedArtwork'],
+      compute: ({
+        ['#constitutedArtwork']: constitutedArtwork,
+      }) => [constitutedArtwork],
+    },
+  ],
+});
+
+template.fromYAMLFieldSpec = function(field) {
+  const {[Thing.yamlDocumentSpec]: documentSpec} = this;
+
+  const {provide} = documentSpec.fields[field].transform;
+
+  const inputs =
+    withEntries(provide, entries =>
+      entries.map(([property, value]) => [
+        property,
+        input.value(value),
+      ]));
+
+  return template(inputs);
+};
+
+export default template;
diff --git a/src/data/composite/wiki-properties/contributionList.js b/src/data/composite/wiki-properties/contributionList.js
index 8fde2caa..d9a6b417 100644
--- a/src/data/composite/wiki-properties/contributionList.js
+++ b/src/data/composite/wiki-properties/contributionList.js
@@ -3,19 +3,19 @@
 // into one property. Update value will look something like this:
 //
 //   [
-//     {who: 'Artist Name', what: 'Viola'},
-//     {who: 'artist:john-cena', what: null},
+//     {artist: 'Artist Name', annotation: 'Viola'},
+//     {artist: 'artist:john-cena', annotation: null},
 //     ...
 //   ]
 //
 // ...typically as processed from YAML, spreadsheet, or elsewhere.
-// Exposes as the same, but with the "who" replaced with matches found in
-// artistData - which means this always depends on an `artistData` property
-// also existing on this object!
+// Exposes as the same, but with the artist property replaced with matches
+// found in artistData - which means this always depends on an `artistData`
+// property also existing on this object!
 //
 
 import {input, templateCompositeFrom} from '#composite';
-import {isContributionList} from '#validators';
+import {isContributionList, isDate, isStringNonEmpty} from '#validators';
 
 import {exposeConstant, exposeDependencyOrContinue} from '#composite/control-flow';
 import {withResolvedContribs} from '#composite/wiki-data';
@@ -25,11 +25,34 @@ export default templateCompositeFrom({
 
   compose: false,
 
+  inputs: {
+    date: input({
+      validate: isDate,
+      acceptsNull: true,
+    }),
+
+    artistProperty: input({
+      validate: isStringNonEmpty,
+      defaultValue: null,
+    }),
+  },
+
   update: {validate: isContributionList},
 
   steps: () => [
-    withResolvedContribs({from: input.updateValue()}),
-    exposeDependencyOrContinue({dependency: '#resolvedContribs'}),
-    exposeConstant({value: input.value([])}),
+    withResolvedContribs({
+      from: input.updateValue(),
+      thingProperty: input.thisProperty(),
+      artistProperty: input('artistProperty'),
+      date: input('date'),
+    }),
+
+    exposeDependencyOrContinue({
+      dependency: '#resolvedContribs',
+    }),
+
+    exposeConstant({
+      value: input.value([]),
+    }),
   ],
 });
diff --git a/src/data/composite/wiki-properties/directory.js b/src/data/composite/wiki-properties/directory.js
index 0b2181c9..1756a8e5 100644
--- a/src/data/composite/wiki-properties/directory.js
+++ b/src/data/composite/wiki-properties/directory.js
@@ -2,22 +2,40 @@
 // almost any data object. Also corresponds to a part of the URL which pages of
 // such objects are visited at.
 
-import {isDirectory} from '#validators';
-import {getKebabCase} from '#wiki-data';
-
-// TODO: Not templateCompositeFrom.
-
-export default function() {
-  return {
-    flags: {update: true, expose: true},
-    update: {validate: isDirectory},
-    expose: {
-      dependencies: ['name'],
-      transform(directory, {name}) {
-        if (directory === null && name === null) return null;
-        else if (directory === null) return getKebabCase(name);
-        else return directory;
-      },
-    },
-  };
-}
+import {input, templateCompositeFrom} from '#composite';
+
+import {isDirectory, isName} from '#validators';
+
+import {exposeDependency} from '#composite/control-flow';
+import {withDirectory} from '#composite/wiki-data';
+
+export default templateCompositeFrom({
+  annotation: `directory`,
+
+  compose: false,
+
+  inputs: {
+    name: input({
+      validate: isName,
+      defaultDependency: 'name',
+      acceptsNull: true,
+    }),
+
+    suffix: input({
+      validate: isDirectory,
+      defaultValue: null,
+    }),
+  },
+
+  steps: () => [
+    withDirectory({
+      directory: input.updateValue({validate: isDirectory}),
+      name: input('name'),
+      suffix: input('suffix'),
+    }),
+
+    exposeDependency({
+      dependency: '#directory',
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-properties/helpers/reference-list-helpers.js b/src/data/composite/wiki-properties/helpers/reference-list-helpers.js
new file mode 100644
index 00000000..dfdc6b41
--- /dev/null
+++ b/src/data/composite/wiki-properties/helpers/reference-list-helpers.js
@@ -0,0 +1,44 @@
+import {input} from '#composite';
+import {anyOf, isString, isThingClass, validateArrayItems} from '#validators';
+
+export function referenceListInputDescriptions() {
+  return {
+    class: input.staticValue({
+      validate:
+        anyOf(
+          isThingClass,
+          validateArrayItems(isThingClass)),
+
+      acceptsNull: true,
+      defaultValue: null,
+    }),
+
+    referenceType: input.staticValue({
+      validate:
+        anyOf(
+          isString,
+          validateArrayItems(isString)),
+
+      acceptsNull: true,
+      defaultValue: null,
+    }),
+  };
+}
+
+export function referenceListUpdateDescription({
+  validateReferenceList,
+}) {
+  return ({
+    [input.staticValue('class')]: thingClass,
+    [input.staticValue('referenceType')]: referenceType,
+  }) => ({
+    validate:
+      validateReferenceList(
+        (Array.isArray(thingClass)
+          ? thingClass.map(thingClass =>
+              thingClass[Symbol.for('Thing.referenceType')])
+       : thingClass
+          ? thingClass[Symbol.for('Thing.referenceType')]
+          : referenceType)),
+  });
+}
diff --git a/src/data/composite/wiki-properties/index.js b/src/data/composite/wiki-properties/index.js
index 89cb6838..e8f109d3 100644
--- a/src/data/composite/wiki-properties/index.js
+++ b/src/data/composite/wiki-properties/index.js
@@ -3,11 +3,11 @@
 // Entries here may depend on entries in #composite/control-flow,
 // #composite/data, and #composite/wiki-data.
 
-export {default as additionalFiles} from './additionalFiles.js';
-export {default as additionalNameList} from './additionalNameList.js';
+export {default as annotatedReferenceList} from './annotatedReferenceList.js';
 export {default as color} from './color.js';
-export {default as commentary} from './commentary.js';
 export {default as commentatorArtists} from './commentatorArtists.js';
+export {default as constitutibleArtwork} from './constitutibleArtwork.js';
+export {default as constitutibleArtworkList} from './constitutibleArtworkList.js';
 export {default as contentString} from './contentString.js';
 export {default as contribsPresent} from './contribsPresent.js';
 export {default as contributionList} from './contributionList.js';
@@ -19,10 +19,15 @@ export {default as fileExtension} from './fileExtension.js';
 export {default as flag} from './flag.js';
 export {default as name} from './name.js';
 export {default as referenceList} from './referenceList.js';
-export {default as reverseContributionList} from './reverseContributionList.js';
+export {default as referencedArtworkList} from './referencedArtworkList.js';
 export {default as reverseReferenceList} from './reverseReferenceList.js';
 export {default as simpleDate} from './simpleDate.js';
 export {default as simpleString} from './simpleString.js';
 export {default as singleReference} from './singleReference.js';
+export {default as soupyFind} from './soupyFind.js';
+export {default as soupyReverse} from './soupyReverse.js';
+export {default as thing} from './thing.js';
+export {default as thingList} from './thingList.js';
 export {default as urls} from './urls.js';
+export {default as wallpaperParts} from './wallpaperParts.js';
 export {default as wikiData} from './wikiData.js';
diff --git a/src/data/composite/wiki-properties/referenceList.js b/src/data/composite/wiki-properties/referenceList.js
index af634a68..4f8207b5 100644
--- a/src/data/composite/wiki-properties/referenceList.js
+++ b/src/data/composite/wiki-properties/referenceList.js
@@ -1,5 +1,6 @@
 // Stores and exposes a list of references to other data objects; all items
-// must be references to the same type, which is specified on the class input.
+// must be references to the same type, which is either implied from the class
+// input, or explicitly set on the referenceType input.
 //
 // See also:
 //  - singleReference
@@ -7,10 +8,14 @@
 //
 
 import {input, templateCompositeFrom} from '#composite';
-import {isThingClass, validateReferenceList} from '#validators';
+import {validateReferenceList} from '#validators';
 
 import {exposeDependency} from '#composite/control-flow';
-import {inputWikiData, withResolvedReferenceList} from '#composite/wiki-data';
+import {inputSoupyFind, inputWikiData, withResolvedReferenceList}
+  from '#composite/wiki-data';
+
+import {referenceListInputDescriptions, referenceListUpdateDescription}
+  from './helpers/reference-list-helpers.js';
 
 export default templateCompositeFrom({
   annotation: `referenceList`,
@@ -18,20 +23,16 @@ export default templateCompositeFrom({
   compose: false,
 
   inputs: {
-    class: input.staticValue({validate: isThingClass}),
-
-    data: inputWikiData({allowMixedTypes: false}),
+    ...referenceListInputDescriptions(),
 
-    find: input({type: 'function'}),
+    data: inputWikiData({allowMixedTypes: true}),
+    find: inputSoupyFind(),
   },
 
-  update: ({
-    [input.staticValue('class')]: thingClass,
-  }) => ({
-    validate:
-      validateReferenceList(
-        thingClass[Symbol.for('Thing.referenceType')]),
-  }),
+  update:
+    referenceListUpdateDescription({
+      validateReferenceList: validateReferenceList,
+    }),
 
   steps: () => [
     withResolvedReferenceList({
diff --git a/src/data/composite/wiki-properties/referencedArtworkList.js b/src/data/composite/wiki-properties/referencedArtworkList.js
new file mode 100644
index 00000000..4f243493
--- /dev/null
+++ b/src/data/composite/wiki-properties/referencedArtworkList.js
@@ -0,0 +1,31 @@
+import {input, templateCompositeFrom} from '#composite';
+import find from '#find';
+
+import annotatedReferenceList from './annotatedReferenceList.js';
+
+export default templateCompositeFrom({
+  annotation: `referencedArtworkList`,
+
+  compose: false,
+
+  steps: () => [
+    {
+      compute: (continuation) => continuation({
+        ['#find']:
+          find.mixed({
+            track: find.trackPrimaryArtwork,
+            album: find.albumPrimaryArtwork,
+          }),
+      }),
+    },
+
+    annotatedReferenceList({
+      referenceType: input.value(['album', 'track']),
+
+      data: 'artworkData',
+      find: '#find',
+
+      thing: input.value('artwork'),
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-properties/reverseContributionList.js b/src/data/composite/wiki-properties/reverseContributionList.js
deleted file mode 100644
index 7f3f9c81..00000000
--- a/src/data/composite/wiki-properties/reverseContributionList.js
+++ /dev/null
@@ -1,24 +0,0 @@
-import {input, templateCompositeFrom} from '#composite';
-
-import {exposeDependency} from '#composite/control-flow';
-import {inputWikiData, withReverseContributionList} from '#composite/wiki-data';
-
-export default templateCompositeFrom({
-  annotation: `reverseContributionList`,
-
-  compose: false,
-
-  inputs: {
-    data: inputWikiData({allowMixedTypes: false}),
-    list: input({type: 'string'}),
-  },
-
-  steps: () => [
-    withReverseContributionList({
-      data: input('data'),
-      list: input('list'),
-    }),
-
-    exposeDependency({dependency: '#reverseContributionList'}),
-  ],
-});
diff --git a/src/data/composite/wiki-properties/reverseReferenceList.js b/src/data/composite/wiki-properties/reverseReferenceList.js
index 84ba67df..6d590a67 100644
--- a/src/data/composite/wiki-properties/reverseReferenceList.js
+++ b/src/data/composite/wiki-properties/reverseReferenceList.js
@@ -1,13 +1,13 @@
 // Neat little shortcut for "reversing" the reference lists stored on other
 // things - for example, tracks specify a "referenced tracks" property, and
 // you would use this to compute a corresponding "referenced *by* tracks"
-// property. Naturally, the passed ref list property is of the things in the
-// wiki data provided, not the requesting Thing itself.
+// property.
 
 import {input, templateCompositeFrom} from '#composite';
 
 import {exposeDependency} from '#composite/control-flow';
-import {inputWikiData, withReverseReferenceList} from '#composite/wiki-data';
+import {inputSoupyReverse, inputWikiData, withReverseReferenceList}
+  from '#composite/wiki-data';
 
 export default templateCompositeFrom({
   annotation: `reverseReferenceList`,
@@ -15,14 +15,14 @@ export default templateCompositeFrom({
   compose: false,
 
   inputs: {
-    data: inputWikiData({allowMixedTypes: false}),
-    list: input({type: 'string'}),
+    data: inputWikiData({allowMixedTypes: true}),
+    reverse: inputSoupyReverse(),
   },
 
   steps: () => [
     withReverseReferenceList({
       data: input('data'),
-      list: input('list'),
+      reverse: input('reverse'),
     }),
 
     exposeDependency({dependency: '#reverseReferenceList'}),
diff --git a/src/data/composite/wiki-properties/singleReference.js b/src/data/composite/wiki-properties/singleReference.js
index db4fc9f9..f532ebbe 100644
--- a/src/data/composite/wiki-properties/singleReference.js
+++ b/src/data/composite/wiki-properties/singleReference.js
@@ -11,7 +11,8 @@ import {input, templateCompositeFrom} from '#composite';
 import {isThingClass, validateReference} from '#validators';
 
 import {exposeDependency} from '#composite/control-flow';
-import {inputWikiData, withResolvedReference} from '#composite/wiki-data';
+import {inputSoupyFind, inputWikiData, withResolvedReference}
+  from '#composite/wiki-data';
 
 export default templateCompositeFrom({
   annotation: `singleReference`,
@@ -21,8 +22,7 @@ export default templateCompositeFrom({
   inputs: {
     class: input.staticValue({validate: isThingClass}),
 
-    find: input({type: 'function'}),
-
+    find: inputSoupyFind(),
     data: inputWikiData({allowMixedTypes: false}),
   },
 
diff --git a/src/data/composite/wiki-properties/soupyFind.js b/src/data/composite/wiki-properties/soupyFind.js
new file mode 100644
index 00000000..0f9a17e3
--- /dev/null
+++ b/src/data/composite/wiki-properties/soupyFind.js
@@ -0,0 +1,14 @@
+import {isObject} from '#validators';
+
+import {inputSoupyFind} from '#composite/wiki-data';
+
+function soupyFind() {
+  return {
+    flags: {update: true},
+    update: {validate: isObject},
+  };
+}
+
+soupyFind.input = inputSoupyFind.input;
+
+export default soupyFind;
diff --git a/src/data/composite/wiki-properties/soupyReverse.js b/src/data/composite/wiki-properties/soupyReverse.js
new file mode 100644
index 00000000..784a66b4
--- /dev/null
+++ b/src/data/composite/wiki-properties/soupyReverse.js
@@ -0,0 +1,37 @@
+import {isObject} from '#validators';
+
+import {inputSoupyReverse} from '#composite/wiki-data';
+
+function soupyReverse() {
+  return {
+    flags: {update: true},
+    update: {validate: isObject},
+  };
+}
+
+soupyReverse.input = inputSoupyReverse.input;
+
+soupyReverse.contributionsBy =
+  (bindTo, contributionsProperty) => ({
+    bindTo,
+
+    referencing: thing => thing[contributionsProperty],
+    referenced: contrib => [contrib.artist],
+  });
+
+soupyReverse.artworkContributionsBy =
+  (bindTo, artworkProperty, {single = false} = {}) => ({
+    bindTo,
+
+    referencing: thing =>
+      (single
+        ? (thing[artworkProperty]
+            ? thing[artworkProperty].artistContribs
+            : [])
+        : thing[artworkProperty]
+            .flatMap(artwork => artwork.artistContribs)),
+
+    referenced: contrib => [contrib.artist],
+  });
+
+export default soupyReverse;
diff --git a/src/data/composite/wiki-properties/thing.js b/src/data/composite/wiki-properties/thing.js
new file mode 100644
index 00000000..1f97a362
--- /dev/null
+++ b/src/data/composite/wiki-properties/thing.js
@@ -0,0 +1,40 @@
+// An individual Thing, provided directly rather than by reference.
+
+import {input, templateCompositeFrom} from '#composite';
+import {isThingClass, validateThing} from '#validators';
+
+import {exposeConstant, exposeUpdateValueOrContinue}
+  from '#composite/control-flow';
+
+export default templateCompositeFrom({
+  annotation: `wikiData`,
+
+  compose: false,
+
+  inputs: {
+    class: input.staticValue({
+      validate: isThingClass,
+      defaultValue: null,
+    }),
+  },
+
+  update: ({
+    [input.staticValue('class')]: thingClass,
+  }) => ({
+    validate:
+      validateThing({
+        referenceType:
+          (thingClass
+            ? thingClass[Symbol.for('Thing.referenceType')]
+            : ''),
+      }),
+  }),
+
+  steps: () => [
+    exposeUpdateValueOrContinue(),
+
+    exposeConstant({
+      value: input.value(null),
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-properties/thingList.js b/src/data/composite/wiki-properties/thingList.js
new file mode 100644
index 00000000..f4c00e06
--- /dev/null
+++ b/src/data/composite/wiki-properties/thingList.js
@@ -0,0 +1,44 @@
+// A list of Things, provided directly rather than by reference.
+//
+// Essentially the same as wikiData, but exposes the list of things,
+// instead of keeping it private.
+
+import {input, templateCompositeFrom} from '#composite';
+import {isThingClass, validateWikiData} from '#validators';
+
+import {exposeConstant, exposeUpdateValueOrContinue}
+  from '#composite/control-flow';
+
+export default templateCompositeFrom({
+  annotation: `wikiData`,
+
+  compose: false,
+
+  inputs: {
+    class: input.staticValue({
+      validate: isThingClass,
+      defaultValue: null,
+    }),
+  },
+
+  update: ({
+    [input.staticValue('class')]: thingClass,
+  }) => ({
+    validate:
+      validateWikiData({
+        referenceType:
+          (thingClass
+            ? thingClass[Symbol.for('Thing.referenceType')]
+            : ''),
+      }),
+  }),
+
+  steps: () => [
+    exposeUpdateValueOrContinue(),
+
+    exposeConstant({
+      value: input.value([]),
+    }),
+  ],
+});
+
diff --git a/src/data/composite/wiki-properties/wallpaperParts.js b/src/data/composite/wiki-properties/wallpaperParts.js
new file mode 100644
index 00000000..23049397
--- /dev/null
+++ b/src/data/composite/wiki-properties/wallpaperParts.js
@@ -0,0 +1,9 @@
+import {isWallpaperPartList} from '#validators';
+
+export default function() {
+  return {
+    flags: {update: true, expose: true},
+    update: {validate: isWallpaperPartList},
+    expose: {transform: value => value ?? []},
+  };
+}