A Beets Plugin for Rateyourmusic

2014-10-28 20:41

Genres are usually neglected in my music library metadata. My primary source for music metadata doesn’t do genres and therefore I tend not to worry too much about them. However, I usually rely on rateyourmusic.com to discover new music, either by peeking at the ratings or by searching through genres of albums that I enjoyed. Rateyourmusic attributes genres to albums based on community voting and keeps a tree of genres whose structure is also voted upon. I tend to find its genre information fairly accurate and more often than not I find myself browsing through the “best” albums of a given genre on the site.

Locally, I use beets to manage my music library. It’s a great piece of software and I’ve been increasingly using its querying capabilities to populate my playlists. Being able to do the same sort of genre-based queries I do on Rateyourmusic locally would therefore be awesome.

Beets has a plugin to fetch genre data from last.fm tags: LastGenre. There are a couple of issues I identify with using last.fm tags as genres:

  1. To be reasonably accurate, one should use the album or track tags. However, those are usually neglected by users, who tend to tag artists mostly.
  2. There’s no hierarchy in the tags (one needs to build it externally). I would like to, for example, be able to search for Ambient and get albums of both Ambient Techno and Dark Ambient.

Taking that into account, I decided to write a plugin to fetch genre information from Rateyourmusic and assign it to albums and items in the beets library: beets-rymgenre. Rateyourmusic doesn’t provide a webservice or API for developers to build upon1 so it’s necessary to scrape for the desired information. Beets is written in Python, and so are its plugins. I have little experience with it and no familiarity with its ecosystem. I ended up using lxml for scraping and requests for the HTTP client, but more lightweight solutions may exist.

I’ve already populated some albums in my library with genre information and I’m happy with the plugin so far. A great plus of having genre information in the library metadata is that now I can ask beets for random albums of a given genre (or set of genres, for that matter) whenever I’m not sure what to listen to next.

  1. There’s actually an open ticket to build a webservice / API for Rateyourmusic open since 2009!