Reading a very interesting history of analog synthesizers and, to a certain extent, electronic music, called Analog Days. I recommend that you pick it up. If you're interested in the history of modern music at all, you might find it interesting. There are chapters about Wendy Carlos, who did the Switched On Bach album, and on Suzanne Ciani, an early New Age artist who used a Moog synth in quite a lot of her early work.

There's also a very interesting chapter that ties the history of the Grateful Dead with Ken Kesey (One Flew Over the Cuckoos Nest), and lots of other experimental music happening in San Fransisco in the 60s and 70s.