U2 are an Irish rock band from Dublin. Formed in 1976, the group consists of Bono (vocals and guitar), The Edge (guitar, keyboards and vocals), Adam Clayton (bass guitar), and Larry Mullen, Jr. (drums and percussion). U2's early sound was rooted in post-punk but eventually grew to incorporate influences from many genres of popular music. Throughout the group's musical pursuits, they have maintained a sound built on melodic instrumentals, highlighted by The Edge's timbrally varied guitar sounds and Bono's expressive vocals. Their lyrics, often embellished with spiritual imagery, focus on personal themes and sociopolitical concerns.