Well, quite funny actually, as this wonderfully illuminating essay on the comic heart of U2 by Bill Flanagan reveals.

This first of two exclusive extracts is taken from the newly published 'U2 The Best of Propaganda'.

When U2 became the biggest band in the world in the eighties, somehow, for many people, they also became one of the most serious. ZOO TV and the nineties U2 shattered that image. Propaganda, the band's official magazine, commissioned Flanagan, then editor of Musician - and on the road with the band in the process of writing his own acclaimed book 'U2 At The End Of The World' - to explore how far the image of a band can depart from the reality!

'I once met an American tourist in Ireland who said she had been having tea in a hotel restaurant when U2 came in and sat at the table behind her. She and her friend could not believe how funny the four of them were - they traded jokes, quips and can-you-top-this punchlines. "They were like a comedy team," she said. "I alwas thought they were serious!"

I can't tell you how many times I've heard similar things from people who only know U2 through the mass media. I met U2 in 1980 and kept in touch with them over the years since. Three years ago they agreed to let me follow them around and write a book about their music and the whole wild circus that revolves around it. If I knew the band pretty well before, I got to know them very well while travelling in buses, planes and automobiles from Mexico to Tokyo, Italy to Australia. When people ask me about all the time I spent with U2, I usually say, "Well I remember a lot of great music and I remember laughing all the time."

The great music people accept, but a lot of folks raise their eyebrows when I say how funny Adam, Bono, Edge and Larry are. Maybe because I knew U2 as people I knew them through the media, I bring a knowledge of their humour to anything I read or write about them. People who see them only through the eyes of journalists may miss that. While one can never underestimate a critic's ability to not get a joke, there must be something in the way U2 operate that keeps their humour from coming through when the tape recorder is turned on and the notepads are out.

The band may be at the disadvantage of people coming at them with serious preconceptions; if someone walks in and starts asking you to explain art, love and God, it's hard to say, "That reminds me of a funny story..." U2 probably also pay the price of restricting most of their interviews to quick sessions in an office or studio. (There's a good reason for that - if they spent as much time doing interviews as the press would like, they'd never have time to make any music.) Reporters don't get the chance to observe the sort of "Hard Days Night" scene that I witnessed in a limousine with U2 heading to the Los Angeles airport:

In the car Bono struggles to get the TV to change channels but it stays stuck on one of those half-hour self-help commercials. Finally in exasperation, Bono says, "Edge, you're the scientist, can you get this to work?" Edge leans over and tries to change the station. Each time he does, it clicks back to the self-help ad. This is very strange. Edge gets down and fiddles with the switches with the furrow-browed dedication of a Louis Pasteur at his Bunsen burner, oblivious as Bono to the fact that Larry is sitting with a remote control by his leg, clicking the channel back each time Edge tries to change it. At last they give up and accepts the infotainment. "Too bad you can't get cable in a car," Larry says. Then he asks if anyone else has seen the Fishing Channel. "Lots of talk about rods and hooks and the one that got away."

Bono says, "I prefer the 'rides bikes, likes boats and lives with the same girlfriend for twelve years' channel." Larry groans and rolls his eyes. Edge asks what they are talking about. Larry explains that Bono's recapping the thumbnail description of him in the new Vogue cover story on U2. Once again a journalist who was given access to the whole band went home and wrote a story that was chock-full of Bono, had a few wise parables from the Edge, and devoted Adam and Larry roughly the same number of words that go on the back of a bubblegum card. Bono says euphemistically, "She painted Larry in bold strokes."

Adam smiles and says to the sullen Mullen, "At least you're not the one she called 'handsome in an ugly way.'"

One of the funniest things U2 do in their conversation with each other is put on voices and play-act different characters. They sometimes kid each other by adopting 'Spinal Tap' poses. An outsider who walks into the middle of this can come away thinking that these guys really ARE spoiled rock stars (though their parodies are so broad that the outsider would have to be lacking any sense of humour himself.) Here's a scene that took place during the recording of Zooropa, when Larry was interrupted in the lavatory by a summons back to his drums:

Larry strolls in in a cocky mood, "What's so important you had to interrupt a perfectly good crap?"

"We need you to do some drumming," Bono answers. Larry says, "Call my manager."

"We sent a letter to Mr Paul McGuinness," Edge says, "requesting your services to play some drums."

"It's the song we were playing last night," Bono says. "Apparently you did a tremendous job but the rest of us ..."

Adam says, "Amazingly enough YOU were fine."

"We face a problem we have faced in the past," Bono explains. "The song has no chorus."

"Aha!" Larry says.

Final part of this extract to follow soon.