During a time when hair bands shared the success and excess that typified the 1980s, the Irish rock band U2, with its honest, heart-on-the-sleeve mentality, became one of the biggest rock bands in the world with its 1987 release of The Joshua Tree.

During a time when Nirvana seemed to slay any and every band that embodied that very excess, U2 responded with a sarcastic grin, reinventing itself with the 1991 release Achtung Baby. And now, with a world in need of a little hope, U2 — with its critically acclaimed All That You Can't Leave Behind, and its hopeful message of peace — seems to be more relevant than ever .

The band formed in 1976 in Ireland when Larry Mullen Jr. (drums) posted a flyer on his high school bulletin board seeking other musicians to form a Beatles and Rolling Stones cover band. Paul Hewson (Bono, lead vocals and guitar), Adam Clayton (bass), Dave Evans (the Edge, lead guitar, keyboards and backing vocals) and his brother Dick Evans, answered the ad. The band chose the name Feedback and performed their first rehearsal in Mullen's kitchen. Dick Evans soon left, and the group changed their name to U2.

U2 got its first break after the 1978 Guinness talent contest, catching the attention of manager Paul McGuinness. Two years later, with the help of the single "Another Day," the band signed a record deal with Island Records. Later that year, U2 released their debut album, Boy, which received critical acclaim for its visionary atmospheric, yet edgy, sound.

U2 soon broke out in America with the 1983 release of War, supported by the politically charged singles "Sunday Bloody Sunday" and "New Year's Day."

Capitalizing on this momentum, U2 teamed up with producers Dan Lanois and Brian Eno in the recording of the ambient and experimental album, The Unforgettable Fire in 1984. The album echoed the band's interest in America with the songs "Pride (In the Name of Love)" and "MLK."

U2 remained successful in the 1980s, selling out stadiums and music stores throughout America. However, it was the 1987 release of The Joshua Tree that established the rock band as one of the premier in the world. Once again teaming up with producers Eno and Lanois, U2 recorded and released the chart-topping singles "With or Without You" and "I Still Haven't Found What I'm Looking For." The singles were the most heavily rotated songs on the radio that year, and landed the band on the cover of Time magazine.

After the success of live E.P.s and vidoes like Under A Blood Red Sky and Wide Awake in America, U2 filmed various other live performances from the tour and to record new songs for Rattle and Hum, a visual and sonic immersion into the heart of American blues and soul. While the album was a hit, music critics, who misunderstood the motivations behind the film, blasted the band for placing themselves in the same category as Bob Dylan, Elvis Presley and Jimmy Hendrix. As a result, the band left the incredibly successful album and tour with a sour taste in their mouths — one that would not go away until the band's release of the Achtung Baby album.

By the time the band was ready to begin recording their next album, tensions at the Berlin studio were running high. Bono and the Edge, later dubbed "The Hats," wanted to experiment sonically with the new material, whereas Larry and Adam, dubbed "The Haircuts," wanted to stick to the traditional and more established U2 sound. The conflict became so heated that the band contemplated breaking up. However, inspiration intervened in an almost mythical way, into one U2's best and most recognizable songs. The band was in the studio, not speaking to each other, when the Edge began playing a beautiful piano melody. Bono stepped to the microphone and began singing "Is it getting better?/ Or do you feel the same?/ Will it make it easier on you/ Now, you've got someone to blame." One by one, the members of U2 came together and wrote "One," which reinstated the band's faith in music and in each other.

The rest of the sonically experimental album, influenced by electronic and dance music was released in 1991 as the album Achtung Baby. On the strength of singles "One" and "Mysterious Ways," the album received critical acclaim and strong record sales. What followed was an elaborate live spectacle called "The Zoo TV Tour," in which Bono pranced around an enormous stage backed by huge television screens and made prank phone calls to the White House. During the middle of Zoo TV, U2 returned to the studio in 1993 and recorded Zooropa.

In 1995, under the disguise of a different name, U2 released The Passengers' first — and only — album. Quite experimental, it was met by lukewarm critical and public response. U2 soon returned to the studio to record their next, and most difficult album, Pop.

Both critics and fans assumed that U2 would retreat from the intentionally bombastic nature of Achtung Baby and ZooTV with a more stripped-down, traditional album. However, the band had other ideas in mind. Pop, released in 1997, was even more techno and dance-influenced than either Achtung Baby or Zooropa, and Pop Mart, the name of the new tour, was even bigger and more visually stimulating than Zoo TV.

Unfortunately, the album and the tour met lackluster sales. Coupled with the enormous price tag of the tour itself, U2 was yet again left at the end of the tour with a sour taste — although this time financial and not critical — in its mouth.

After the seemingly disastrous Pop Mart, the band regrouped and reinvented itself yet again. Bono and the Edge began writing songs for the All That You Can't Leave Behind outside of the studio; something the band had not done in almost 20 years. The band also changed its focus, stripping away the glamorous glaze left over from the ZooTV and Pop Mart tours. What emerged was one of the most honest albums U2 has ever recorded. Released in 2000, All That You Can't Leave Behind, riding on the strength of such singles as "Beautiful Day" and "Elevation" was met with energetic and excited applause, both critically and publicly.

U2 has evolved over the years from an earnest and idealistic group of teenagers to one of the best rock bands of this generation. The band's latest album sings of a wiser yet still hopeful U2, one that seems to touch even more people, especially given the events of September 11. The world needs a hopeful voice, and that voice is U2.

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