Like many huge rock bands, U2 didn't emerge fully formed and ready for stardom. The group's very first meeting on Sept. 25, 1976, was casual at best – and wouldn't have happened at all without the urging of drummer Larry Mullen Jr.'s dad.

As the story goes, the elder Mullen saw how passionate his 14-year-old son was about music — Mullen Jr. had been taking drum lessons and was itching to form a rock band — and was supportive of this dream.

"We didn't always see eye to eye, but through it all, he was still watching my back," Mullen Jr. said in the book U2 by U2. "He was figuring, 'OK, the kid wants to play drums. How do I help him survive and navigate this, because he's never going to be a brain surgeon.'"

Mullen Sr.'s solution was simple: Post a "musicians wanted" ad at school, the Mount Temple Comprehensive School in Dublin, Ireland. "I think the wording went something like: 'Drummer seeks musicians to form band,'" Mullen Jr. recalled. "I just thought of it as a bit of fun. It was never anything else. No big ideas, no expectations."

Still, the notice did the trick at attracting the right people. At the infamous first meeting in Mullen Jr.'s kitchen, U2's future core members were present: vocalist Paul Hewson (a.k.a. Bono), guitarist David Evans (The Edge) and bassist Adam Clayton. Edge's older brother Dick Evans was also there as a guitarist, as was Peter Martin—whose gear the teens had borrowed—and guitarist Ivan McCormick.

The future members of U2 were at least aware of one another before playing music together. Edge had attended a previous school with Clayton, while Bono's reputation preceded him: Edge recalled seeing the teenager during lunch period "trying to impress some girls" by playing Beatles songs.

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Whether he was successful is lost to time, although this scene made an impression on the aspiring guitarist. "I couldn't help but observe that I was a better player, and yet he was more popular," Edge said in U2 by U2. "I made a mental note that perhaps the way you carried your guitar was as important as how well you could play it."

That confidence and charm was on display during the group's very first get-together. "It was 'The Larry Mullen Band' for about ten minutes, so as not to hurt my feelings," Mullen Jr. admitted. "It was also my kitchen. Then Bono came in and that was the end of that. He blew any chance I had of being in charge."

McCormick and Martin ended up dropping out of the band rather quickly; Edge's brother also faded from the picture. However, the remaining core four decided on the name Feedback and began working to get better.

The musicians drew on varied influences. Although all four members agreed on T. Rex and David Bowie, the Edge was into Rory Gallagher, Bono preferred the Beach Boys and early rock 'n' roll, and Mullen Jr. liked the Eagles thanks to his sister.

According to U2gigs.com, the band's first show as Feedback took place sometime later in 1976 at Mount Temple, during a talent show at the end of a semester.

The young group played a 10-minute set of cover songs that included Peter Frampton's "Show Me the Way," the Bay City Rollers-popularized "Bye, Bye, Baby (Baby Goodbye)" and a medley of Beach Boys songs.

"I think the truth is they were the only songs we could play all the way through," Edge confessed years later.

Paying work for Feedback wouldn't arrive until April 1977, when they played another covers-heavy gig at Dublin's St Fintan's School. However, by then the group was off and running—and success followed sooner than anyone dreamed.

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U2 don't inspire weak reactions in people. There are passionate U2 fans, and passionate U2 haters, and very little in between.

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