Unifying theory of pop music history?

At the risk of offending many, I have admit that I am not a fan of the Beatles. This made me very excited to read the book How the Beatles Destroyed Rock'n'Roll. I was looking forward to a long screed about how the Beatles lead rock down a blind path away from the gritty goodness that came before. The book was actually devoid of Beatle-bashing.

What I got instead was a readable and enlightening trip through American pop music history from around 1870 to around 1970. The author showed how three steady trends reached new levels with the Beatles:
1. The effect that technology has on music tastes.
2. The movement from music for dancing to music for listening.
3. The increased separation between the music whites and blacks consume.

Very cool book!