To begin with, the key principle of American indie rock wasn't a circumscribed musical style; it was the punk ethos of DIY, or do-it-yourself. The equation was simple: If punk was rebellious and DIY was rebellious, then doing it yourself was punk. 'Punk was about more than just starting a band,' former Minutemen bassist Mike Watt once said, 'it was about starting a label, it was about touring, it was about taking control. It was like songwriting; you just do it. You want a record, you pay the pressing plant. That's what it was all about.'

For Nirvana, putting out their first major-label record was like getting into a new car. But the runaway success was like suddenly discovering that the car was a Ferrari and the accelerator pedal was Krazy Glued to the floorboard.

You didn't have to be a huge rock star; you just had to do well enough to continue doing what you wanted to do. It wasn't about hitting the jackpot, it was about sustainability.

Bon Jovi's trick is to use heavy-metal chords and still sound absolutely safe. Rock & roll used to be rebellion disguised as commercialism; now so much of it is commercialism disguised as rebellion.

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.

A lot of music fans are still interested in insightful perspectives on music - maybe even more interested than ever, since everyone needs help making sense of the incredible variety of sounds that have sprung up in the wake of the Internet revolution. There's a lot of room for unique, qualified voices who can provide good reads.

I really believe in the power of music - and I mean literally the power of musical tones - to rearrange the way you can think.