I worked on two cool open source music technology projects called ListenBrainz [1] (basically an open source version of Last.FM backed by the MetaBrainz Foundation, the people behind MusicBrainz) and AcousticBrainz [2] (a project trying to crowdsource acoustic information about music and release it as public domain). We released a beta for ListenBrainz over the summer and I've been working on data dumps for both ListenBrainz and AcousticBrainz for the past few weeks.
[1] https://listenbrainz.org/
[2] https://acousticbrainz.org