It is a streaming service with zaps and you can log in with nostr. It was around before nostr so I think it's still a site rather than a true decentralised nostr implementation. It is the kind of thing that nostr could develop a unique niche.

A nostr music player could allow content producers to be paid directly for their material. That would allow more diversity because content wouldn't be controlled by record labels.

In theory you could search other people's liked songs to discover songs you like.