Q&A

That's how Bono described the late-night sessions he and the Gateses have when they get together. In an interview with Josh Tyrangiel in Omaha last week, the rapport between the rocker and the tech lords was easy and their curiosity about one another's worlds genuine.

TIME When you first had Bono over for dinner, in 2002, were you aware of his celebrity or nervous about it?

MELINDA GATES: We'd certainly never had a rock star to the house before, but the whole reason we got together is because we have this joint cause. [To Bono] I have to be honest, we kind of came a lot later to your music than other people.

BONO: It was fresh not to be seen as a celebrity but as a piece in the puzzle of how we communicate the jeopardy of all those lives--and the opportunity of helping if we can just agree on something. It was nice not to be asked how the Achtung! Baby sessions went in Berlin.

M.G.: The first U2 concert we went to was in Seattle quite a bit later, and when you came out onstage, our reaction was quite different from your other fans'. It was more like "Oh, my gosh, does he know that all these people are here watching him? Oh, I hope he's O.K."

TIME Are you bigger music fans now?

BILL GATES: I've always been a music fan. Paul [Allen, Microsoft's co-founder] played guitar and made sure I knew all the Jimi Hendrix songs. He's a real music nut. Not many people create a music museum. [Allen founded Seattle's Experience Music Project.]

B.: You couldn't not listen to music if Paul Allen was your partner. So Jimi Hendrix helped form [slipping into a monster-movie voice] "the Brain of Bill!"

B.G.: Paul would always say, "Are you experienced?" And it would mean different things at different times.

B.: We can ask Melinda about that.

[Laughter]

TIME Maybe next year. All of you deal with quite serious scientific and political issues, but there must be an emotional toll. Who's more likely to get angry or frustrated by the situation?

B.G.: World health is something where, when you first realize the situation, it's pretty stark and even a bit depressing--just the magnitude of the inequity. But the more you work on it, you see the improvements that are taking place--that decade by decade new medicines are getting there. Maybe not as fast as they should, but you see the trajectory.

M.G.: When you visit a new country, you think, Oh, my gosh, maybe this is the time that I'm going to go somewhere and feel like there's no hope. But I don't think we've ever been in a situation where there hasn't been some glimmer.

B.: I get angry all right--but at myself and our inability to tell the story, to get the news out that this need not be a burden but instead an adventure. But that anger is much more than made up for by the nobility of these people and their entrepreneurial nature. And then you see what a new medicine can do. Three years ago, the idea that nearly half a million Africans would be on antiretrovirals paid for by the U.S.A. was absolutely preposterous. That more than repays the anger.

TIME You all have high-profile, time-consuming day jobs. Do you draw clear lines between your day jobs and this stuff?