Importing genres and labels

Stars have positions and routes between them. This import gives them a character: what kind of music each artist makes, and which imprints pressed it.

Run the MusicBrainz import first. Artists are joined to their Discogs entries through MusicBrainz’s own discogs URL relationship, so without the canon there is nothing to attach genres to.

Why Discogs and not MusicBrainz

MusicBrainz does carry genres — as folksonomy tags, in mbdump-derived.tar.bz2, which is licensed CC BY-NC-SA 3.0. That restriction travels to everything computed from the data, and genres feed the sky layout, the tiles and everything drawn from them. The Discogs dumps are CC0, so the canon stays public domain end to end. The full reasoning is in ADR 0005.

Get the dumps

The dumps live behind an index at data.discogs.com. Object URLs take a ?download= parameter — a plain path returns the HTML index with a 200, so check what you actually downloaded:

base='https://data.discogs.com/?download=data%2F2026%2F'
for file in CHECKSUM.txt masters.xml.gz labels.xml.gz artists.xml.gz; do
  curl -sL -o "discogs_20260801_$file" "${base}discogs_20260801_$file"
done
sha256sum -c discogs_20260801_CHECKSUM.txt

Three files are needed, about 1.15 GB together:

File	Size	What it gives
masters.xml.gz	593 MB	The genres and styles themselves
labels.xml.gz	86 MB	Labels, their descriptions and ownership
artists.xml.gz	472 MB	Optional: verifies that credited ids exist

Do not download releases.xml.gz. It is 10.4 GB and adds nothing: a master release already carries the genres of all its pressings.

Run the import

lyrid import discogs \
  --masters ./discogs_20260801_masters.xml.gz \
  --labels  ./discogs_20260801_labels.xml.gz \
  --artists ./discogs_20260801_artists.xml.gz

Each file is read in one streaming pass — nothing is held in memory whole — and everything is written in one transaction, so an interrupted run leaves the previous genres standing. On a full 2026-08 dump set the whole import took about two and a half minutes.

INFO lyrid::import::discogs: resolving Discogs data against the canon linked=…
INFO lyrid::import::discogs: artists file read records=10163318 linked_found=…
INFO lyrid::import::discogs: masters file read records=2579897 artists_with_genres=… credits_counted=…
INFO lyrid::import::discogs: labels file read records=2405196 kept=2405195
INFO lyrid::import::discogs: genre vocabulary written rows=…
INFO lyrid::import::discogs: artist genres written rows=…
INFO lyrid::import::discogs: labels written rows=2405195 parents=139304

--labels and --artists are both optional. Without --labels the labels table is left as it was; without --artists the import skips checking that the ids credited on a master actually exist in the artists file.

The version defaults to the date in the masters filename (discogs_20260801_masters.xml.gz → 20260801). Pass --dump-version if your files are named differently.

Genres are weighted, not boolean

Discogs attaches genres to releases, never to artists, so an artist’s genres are aggregated over their discography — and the number of releases behind each one is kept:

SELECT g.name, g.is_style, ag.releases
FROM artist_genre ag
JOIN genre g ON g.id = ag.genre_id
JOIN artist a ON a.id = ag.artist_id
WHERE a.name = 'Nirvana'
ORDER BY ag.releases DESC
LIMIT 5;

      name       | is_style | releases
-----------------+----------+----------
 Rock            | f        |      314
 Grunge          | t        |      303
 Alternative Rock| t        |      113
 Acoustic        | t        |       14
 Punk            | t        |       13

The weight is what makes this usable. A discography’s tail is full of remixes, interviews and compilation appearances that would each count as much as the main body if genres were a yes-or-no fact. Threshold on releases rather than treating presence as membership.

is_style separates Discogs’s two depths: false for a genre (“Electronic”), true for a style (“Techno”).

How an artist is matched

Through MusicBrainz’s discogs artist-URL relationship, never by name:

SELECT a.name, ad.discogs_id
FROM artist_discogs ad
JOIN artist a ON a.id = ad.artist_id
LIMIT 5;

Names collide constantly — Discogs disambiguates with numeric suffixes like “Jack Jones (4)” precisely because they do — and a name-based join would put one artist’s genres on another. URLs under the same relationship kind that point at label or release pages are ignored.

An artist with no Discogs link gets no genres. That is expected: it is the same dark matter at the map’s margins that missing similarity produces.

Labels

Labels are the stations of the map, and they nest:

SELECT l.name, p.name AS parent
FROM label l JOIN label p ON p.id = l.parent_label_id
WHERE l.name = 'Svek';

 name |     parent
------+----------------
 Svek | Goldhead Music

Contact blocks are deliberately not imported. They carry postal addresses and personal e-mail of small-label owners, and this product has no use for them.

Re-importing

Importing again replaces genres, links and labels wholesale and updates the dump_import record rather than adding a second one. Verified against the full dumps: a second run produced identical counts with no duplicates.