Sourcing and selection
Catalog Methodology
This page explains what the playable totals mean, where preview metadata comes from, which tracks are filtered, when snapshots change, and how to request a correction.
1. Apple Music catalog and preview sourcing
The catalog sync queries Apple Music catalog endpoints for each configured artist, primarily through the United States storefront. Regional availability can therefore affect whether a release has usable metadata or a preview.
A track must include a preview URL supplied in Apple Music catalog data. During a game, the browser plays progressively longer segments of that preview: 1, 2, 4, 7, 10, 15 seconds. The site does not proxy those audio files through its own catalog endpoint or host full recordings.
Apple Music does not sponsor or operate K-Pop Heardle. Catalog metadata and preview availability are inputs to an independent fan-made game, not evidence of an official partnership.
2. Eligibility and version filters
The catalog sync applies eligibility rules and deduplication before storage. The game and displayed totals then apply the current runtime filter chain to the stored snapshot. A track may be excluded when:
- Its title or preview URL is missing.
- Its title contains non-ASCII characters that the current matching interface does not support consistently.
- Its title identifies a remix, instrumental, live recording, demo, edit, alternate mix, language version, or similar variation.
- It is labeled as an intro, outro, interlude, skit, or other non-standard game entry.
- Its album or title patterns indicate a duplicate or remix release.
- A cleaner duplicate version of the same track is retained instead.
These are availability and game-consistency rules, not judgments about a song's quality. Pattern-based filters can make mistakes, which is why corrections are accepted.
3. Snapshot refresh and activation
An automated workflow normally refreshes configured artists each evening at approximately 10:00 PM America/Los_Angeles time. Each artist is written as a dated catalog generation rather than changing the active song list in place.
A normal refresh is staged for the next canonical day and becomes eligible at midnight in America/Los_Angeles. This prevents a catalog update from changing the pool underneath a daily challenge already in progress.
Song rows are replaced atomically within a generation. If one artist fails to refresh, the workflow reports the failure and that artist's existing active snapshot remains available. Artist pages label whether their displayed facts use the active database snapshot or an offline fallback snapshot.
4. What the totals mean
Eligible songs is the number of tracks remaining after the current runtime filter chain.
Albums and releases counts unique normalized album names represented by those eligible tracks.
Catalog active date identifies the snapshot summarized on the page.
These values describe the playable pool, not an artist's complete official discography.
5. Daily and practice selection
Daily mode locks one shared song for an artist and canonical date. A later refresh does not replace an answer already served for that date.
Practice mode draws random rounds from the current eligible pool. It is separate from the daily result and does not change daily statistics.
Public pages show aggregate catalog facts only. They never server-render or disclose the current daily answer.
6. Editorial review and corrections
Automated catalog facts are kept separate from editorial claims. Reviewed artist context displays a review date and links to official artist or label sources. News articles identify their official source and show publication and modification information.
If a song is missing, a filtered version is wrong, a preview is broken, or a factual statement needs correction, include the artist, title, page URL, and an official source in a report. A dedicated correction channel is under construction.
Methodology reviewed July 21, 2026.