I am reading "The Rest Is Noise" by Alex Ross. Interesting review of 20th Century avant-garde music. Mostly focuses on classical composers, like Berg, Varese, and Adams (not the one who invented Pinkberry). But I guess that it goes into bands like Pere Ubu and Husker Dude later on...I am not there yet.
Avant-garde classical music was never much to my liking. But the book does a great job giving the music historical context, which breathes life into it. Schoenberg turns out to be the real punk rocker, basically spitting on everything that came before him. Too bad I find his twelve-tone music unlistenable, even with historical context. It seems to me like music for classically-trained musicians, like Richard Foreman is a playwright for playwrights.
And if describing music through text seems like a bad idea, Ross has some playlists on iTunes to supplement the reading. Good for novices like myself.