A sufficiently seeded torrent is a high latency static CDN.
You just need a client that can make use of it.
I'm not sure if anyone will be interested in making one however, you can already get a patched Spotify APK from the usual mobile piracy spaces that's good enough.
Now that's a cool idea.
Wasn't popcorn-time basically video streaming backed by torrent ? Why can't it be the same for audio ?
The metadata is 200 GB which can be easily indexed and could be made searchable, then you download only what you need