In his short story Melancholy Elephants, Spider Robinson advanced the theory that as there are a limited number of songs, thanks to the number of discrete notes that exist, and only a small fraction of these are pleasant songs, extending things like copyright beyond a certain point can actually be harmful as humanity becomes like elephants. Nothing will be ever forgotten, all that can be done will be done, and we will have our noses rubbed in this fact. Enforcing forgetfulness helps.

In short, everything is discovered, not just music.