Playing in my early bands, working as a studio musician, producing and going to art school was, in retrospect, my apprenticeship. I was learning and creating a solid foundation of ideas, but I wasn't really playing music.

There's such a currency to Led Zeppelin, or the members of Led Zeppelin. If I put it to you this way, on the run-up to the O2 concert, the only music that we played was music of Led Zeppelin - the past catalog stuff; that's what we played on the way towards shaping up the set list for that. But we played really, really well.

You get a chance like that maybe once in your lifetime, and you are lucky to sustain it over that period of time. It doesn't mean to say that whatever I do in the future has no substance to it - I may present some new material I've got, and there are definitely new angles of doing it - but I'm not looking to recreate another Led Zeppelin.

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.