My vocation is more in composition really than anything else - building up harmonies using the guitar, orchestrating the guitar like an army, a guitar army.

So far I've been very, very fortunate because it appears that people like to hear the music I like to play. What more fortunate position can a musician be in?

A lot of people can't be on their own. They get frightened. Isolation doesn't bother me at all. It gives me a sense of security.

But if you want me to knock Kingdom Come, all I will say is that I heard the guitarist said he'd never heard my playing, and I'd defy any guitarist in American not to have heard Led Zeppelin.

The key to Zeppelin's longevity has been change.

Led Zeppelin didn't get that kind of Beatles screaming. We had a more sort of macho crowd. But I remember once in the early days of The Yardbirds, we were playing on an ice rink, and the stage was mobbed by screaming girls. I had my clothes torn off me. That's a really uncomfortable experience, let me tell you.

I don't like to tell people what format they can get things in, or say, "I'm only going to release this on vinyl and nothing else. You have to come to my world." I don't like to say that to people either. But, I do think there's a loss of romance.