I was looking for books that discuss the evolution of music in the 20th century, especially the second half.
If it's a book about the history of Rock & Roll, that's fine too.
Hopefully something that talks about the various bands and genres that formed and evolved from 1950's till the end of the 1990's.
It doesn't have to be a book, it can be a website as well. I was thinking of something like A History of Rock and Dance Music by Scaruffi. I would read that one, but some of the reviews about it were very discouraging.