You would find in a lot of Zep stuff that the riff was the juggernaut that careered through and I worked the lyrics around this.

How can you consider flower power outdated? The essence of my lyrics is the desire for peace and harmony. That's all anyone has ever wanted. How could it become outdated?

I've been scared and I've liked not hanging on to stuff where I know that I'm in my comfort zone.

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.

The trouble is now, with rock'n'roll and stuff, it gets so big that it loses what once upon a time was a magnificent thing, where it was special and quite elusive and occasionally a little sinister and it had its own world nobody could get in.

You have to ask these questions: who pays the piper, and what is valuable in this life?