Thank you! Roadmaps with checklists are always interesting. 
What data are you sharing or planning to share, to artists/labels and/or publicly? Your doc only mentions “Keep track of your sales and income”. Are you considering statistics about how many times tracks are played? Logged in users playing them?
Also, are you considering listing the users who have purchased an album, like Bandcamp does?
And something sorely missing in fair platforms (unless I missed it somewhere) are automatic recommendations based on [something reasonable and basic, no complex algorithms]. Whenever I land in a Mirlo track / album / artist, I listen, the song ends, and… that would be the perfect time to queue up another track, somewhat related. But no, music stops and most of times I leave, because I’m not in the mood of starting a new search.
And no Playlists?
Just curious about your thoughts on these features. I’m not pushing for them, and I’m aware feature creep is a very real problem.