For whatever reason, I had to listen to Fugazi's Margin Walker. It has a different sound than what Fugazi went on to make, so it's basically a musical orphan. Kind of like how Buddy Holly's music was an orphan for ~50 years until ppl picked up the threads of his thought again.

How do you find the song that is most like a given song, I asked a coworker over lunch. They said Spotify has a "Radio" feature where you just drop in some songs, and it'll generate a similar playlist for you. That's mostly correct, however Spotify is probably actually answering the programming question, "given how much money we get from you, what's the minimum ASCAP-fee playlist that will likely keep you happy?"

Since Spotify has real costs there, we'll probably someday soon see generated music appearing in your "Radio" playlists. 0 ASCAP fees will be pretty hard to beat.

That said, it would still be cool to have a metric space for songs based on the musical attributes (frequencies, tempo, etc.).