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Bono says he worries about U2 becoming irrelevant.

In an interview with the BBC, he says when working on the band's still unfinished new album he "poured what I'm going through now back through the eye of the experience I had when I first started being in a band and that's what opened me up. If that is relevant to other people, then great; that would be a thrill. But we don't know."

He adds, "I think 'Invisible' is a great song, but I don't know how accessible it is. We'll find out if we're irrelevant. I'm perfectly prepared for people to try and blow us off the stage. We're just not going to make it easy."

Well, Bono, three-million people seemed to think U2's "Invisible" was relevant -- that's how many times the song was downloaded for free as part of a promotion with for his RED charity. Bank of America matched each download with a dollar, meaning a little more than $3 million was donated to RED. "Invisible" will stay up on iTunes and cost $1.29, with all the money from purchases going to fight AIDS.