You’ve described a share in a private company. Not only do you not need an NFT for that, using an NFT provides you no additional guarantees.
When people purchase songs though the smart contract, part of the value can be automatically sent to the wallet of the person who owns the NFT that corresponds to that song.
The problem is most people, even on here still think NFTs are just some dumb pointer.
And if they only allow people to compensate artists through cryptocurrency, then it's not viable for artists.