I know that bands that haven't put out a record for 10 years are playing to 20,000 people a night. But that's not the achievement.

Led Zeppelin has been there through three generations of teenage angst. And there's a generation of kids now who won't know it, post-Linkin Park.

It's crucial that I kind of keep up, without drifting into the backslapping land of cliche and lifetime achievement awards.

I'd break out in hives if I had to sing (`Stairway to Heaven') in every show. I wrote those lyrics and found that song to be of some importance and consequence in 1971, but 17 years later, I don't know. It's just not for me. I sang it at the Atlantic Records show because I'm an old softie and it was my way of saying thank you to Atlantic because I've been with them for 20 years. But no more of `Stairway to Heaven' for me.

And there are certain songs that are really timepieces and shouldn't be touched. But some of them are a celebration of good humour and sensibility and I think that's okay. I don't care about the past, I'm a musician with ambition.

I was young - I was 20 years old. Now I have the gift of perspective and I feel pretty good about it.

I'm too old for Led Zeppelin.