I found this interesting: despite her locally being a big star, Bruce Springsteen sold his music for $550 Million recently which must deflect decades of staying power. https://www.nytimes.com/2021/12/15/arts/music/bruce-springst...

Otoh, Bob Dylan sold his for only $150-200 M. I wonder if he didn't have full rights, or if I'm overestimating his popularity. https://www.nbcnews.com/pop-culture/pop-culture-news/bob-dyl...

Anyway, I'd expect these long standing acts to have more long term value than more modern pop acts like Perry. It would/will be interesting to see the valuations of different artists work.