Enjoy over 30k hours of creative commons music, freely shared.
FunkWhale is another decentralized service like Lemmy or Mastodon. (It also runs on ActivityPub under the hood.) Most of the publicly available pods only share creative commons material, simply because it’s the easiest to share, but artists can share under whatever license works for them.
If you’re technically inclined, you can run your own pod and load whatever music you own onto it, and share it with others (I presume you’ll take care not to share beyond whatever license you have permits). Pods sharing pirated music exist, and they obviously should be avoided. Even if you’re not technically inclined, many pods allow you to upload some amount of music, you’ll want to double check the server’s rules to determine if that can be used for your personal library.