The American indie underground made music for like-minded people who thought for themselves. Thinking for yourself is intrinsically subversive.

Naturally, no one knows more about music than musicians. They talk about their own work all the time, but they rarely get to talk about other people's music.

There's no law that says anybody has to do an interview.

The most surprising and rewarding chapter to write was the Butthole Surfers chapter. I'd always thought of them as a bunch of drug-addled reprobates - which maybe they were - but it turned out to be more complicated than that.

I'm not sure I ever try to make a case for the music. I mean, sometimes the music isn't even that good. I just tell the band's stories; if I describe the music, it's to explain how it moved the overall story along.

Nine Inch Nails' sound is dominated by clanging synths and sardonic, shrieking vocals.

Now that the generation that grew up on '80s indie-rock has attained influential positions in the culture, that music is the new yardstick. And that will shift yet again some day.