You can't just find yourself doing something and not happy doing it.

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.

Once I get onstage the tension explodes and I'm fine. I'm in another world - in a trance almost, doing what I love best, expressing myself through guitar.

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.

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.

There will be a Led Zeppelin as long as there's a Jimmy Page, John Bonham, John Paul Jones and Robert Plant. This isn't a nostalgia band playing the hits forever. If anything ever happened and somebody left - which I really can't see happening - I don't think we'd bother to carry on. The magic for me is as it is now.

Music can always be a life-changing experience, for musicians and fans, or at least life-affecting, but it depends on to what degree.