U2 is a rock band from Dublin, Ireland. The band consists of Bono (vocals and guitar), The Edge (guitar, keyboards, and vocals), Adam Clayton (bass guitar) and Larry Mullen, Jr. (drums and percussion). The band formed in 1976 when the members were teenagers with limited musical proficiency. By the mid-1980s, however, the band had become a top international act, noted for their sound, Bono's impassioned vocals, and The Edge's textural guitar playing.
Their success as a live act was greater than their success at selling records until their 1987 album The Joshua Tree increased the band's stature "from heroes to superstars," according to Rolling Stone. U2 responded to the dance and alternative rock revolutions and their own sense of musical stagnation by reinventing themselves with their 1991 album Achtung Baby and the accompanying Zoo TV Tour. Similar experimentation continued for the rest of the 1990s. In the early 2000s, U2 pursued a more conventional rock sound that retained the influence of their previous musical explorations, before expressing an interest in experimenting with their sound once again for their upcoming twelfth album.
U2 have sold more than 140 million albums worldwide and have won 22 Grammy Awards, more than any other band. In 2005, the band was inducted into the Rock and Roll Hall of Fame in their first year of eligibility. Rolling Stone magazine listed U2 at #22 in its list of the 100 greatest artists of all time. Throughout their career, as a band and as individuals, they have campaigned for human rights and social justice causes, including Amnesty International, the ONE Campaign, and Bono's DATA (Debt, AIDS, Trade in Africa) campaign.