There are very few people I can call real, close friends. They're very, very precious to me.

I may not believe in myself, but I believe in what I'm doing.

I really wasn't needed... Just straightening up riffs, that's all. Just two guitarists doing it instead of one.

Many people think of me as just a riff guitarist, but I think of myself in broader terms. As a musician I think my greatest achievement has been to create unexpected melodies and harmonies within a rock and roll framework. And as a producer I would like to be remembered as someone who was able to sustain a band of unquestionable individual talent, and push it to the forefront during its working career. I think I really captured the best of our output, growth, change and maturity on tape - the multifaceted gem that is Led Zeppelin.

Right from the first time we went to America in 1968, Led Zeppelin was a word-of-mouth thing. You can't really compare it to how it is today.

The guitar to me, from the classical/gut-string guitar right through to Hendrix, et cetera, has all the range [of sound]. Within those six strings it is incredible what one can get sound-wise. It's just down to imagination, really.

You can't overthink the music. Mood and intensity can't be manufactured. The blues isn't about structure; it's what you bring to it. The spontaneity of capturing a specific moment is what drives it.