If you're working at the factory and you're cursing every day that you get up, at all costs get out of it. You'll just make yourself ill.

There's a very old recording maxim that goes, 'Distance makes depth.' I've used that a hell of a lot-whether it's tracking guitars or the whole band. People are used to close-miking amps, but I'd have a mic out around the back, as well, and then balance the two. Also, you shouldn't have to use EQ in the studio if the instruments sound right. You should be able to get the right tones simply with the science of microphone placement.

I always thought the good thing about the guitar was that they didn't teach it in school.

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.

From the classical guitar right through to the furthest electrical experiments and everything in-between, it's amazing what the guitar can actually do. I mean, when one thinks about sounds.

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

We were never a band that did 96 takes of the same thing. I had heard of groups that were into that kind of excess around that time. They'd work on the same track for three or four days and then work on it some more, but that's clearly not the way to record an album. If the track isn't happening and it creates some sort of psychological barrier, even after an hour or two, then you should stop and do something else. Go out: go to the pub, or a restaurant or something. Or play another song.