It's an interesting discussion. Also, a lot of stuff from the 19th century only became famous after copyright expired (and only sometimes was the author able to profit from this, other times they died in poverty.)

28+28+... might be a better model. I know there's a bunch of decent stuff from the 1990s which will never again have any real economic value, but would be fine for soundtracks or tictoks or MAME or etc.