TL;DR - NFTs help prove ownership without needing a central authority (which is a big deal) e.g. have you ever been misled and bought a fake concert ticket? It's also huge for the collectibles market which is plagued with high-levels of fraud (which is a billion dollar industry).
- NFTs can also make fractionalized ownership more accessible. So using your analogy, as an artist I release a song but I sell fractions of my song as NFTs to my audience and when I receive royalties it automatically gets distributed to all the nft song owners.
There will be meme NFTs of course (the cat that got sold for $600k), it is a speculative asset that people are experimenting with but I think eventually things will reset and the useful NFTs will remain. They can have real utility whether for a virtual or physical world.