328 recording_releases with mismatched MB recording/release links

[dprodger]

Problem

After completing the backfill_mb_track_titles backfill, 328 recording_releases remain with NULL track_title because the recording MusicBrainz ID does not appear in the MusicBrainz release tracklist.

Scope: 328 recording_releases across 291 releases, involving only 104 distinct recordings.

Root cause

MusicBrainz sometimes uses different recording IDs for the same performance across different releases (e.g., remastered versions, compilation edits). Our importer linked the recording to the release, but MB tracklist for that release references a different recording ID for the same track.

Top affected recordings

Mismatched releases	Recording
51	Blue in Green
24	All Blues
22	I Concentrate on You (alternate take)
16	We'll Meet Again
13	I Didn't Know What Time It Was (alternate take)
13	Who Cares?
13	Autumn Leaves

Possible approaches

• Fuzzy match by title: For each mismatched recording_release, look up the MB release tracklist and match by title similarity instead of exact recording ID. Set track_title from the best match.
• Re-link recordings: If the MB release tracklist has a recording that matches by title/duration, update our recordings.musicbrainz_id or create the correct recording and re-link.
• Accept and populate from recording title: For these 328 cases, fall back to using recordings.title as the track_title since they are likely identical or very close.

Query to find these

SELECT rr.id, rec.title, rec.musicbrainz_id, rel.title as release_title, rel.musicbrainz_release_id
FROM recording_releases rr
JOIN recordings rec ON rr.recording_id = rec.id
JOIN releases rel ON rr.release_id = rel.id
WHERE rr.track_title IS NULL
  AND rel.musicbrainz_release_id IS NOT NULL
  AND rec.musicbrainz_id IS NOT NULL;