I follow my favorite Lemmy users on Mastodon – since they’re both on activitypub, you can use the one from the other. I like it much better because that’s kinda Mastodon’s whole jam, following users. Here’s what it looks like from Mastodon looking at my account
The answer is yes! It’s called FunkWhale.
I doubt it’ll be what you’re imagining, though, because of the licensing requirements for music hosted in a decentralized system. In particular, everything in the fediverse is public, so all music and podcasts hosted in the fediverse has to be licensed under the creative commons, and can’t be gated to paying customers, which does not include most music or podcasts.
I’m trying to get a team together to do something similar which you can join if you’re interested: https://dougs-digital-garden.netlify.app/notes/trailsapp/