U2's Bono was one of the few real rock heroes of the 1980s, leading the Irish band to international recognition with a charged, political approach to music. The band's early efforts brought a stadium-size presence to alt-rock, with Bono's expressive vocals and the Edge's distinct guitar lines interacting seamlessly with the rhythm section of bassist Adam Clayton and drummer Larry Mullen, Jr. In 1987, U2 broke through to superstardom with THE JOSHUA TREE, a grand culmination of their '80s sound. In the 1990s, however, the band very purposefully deflated that epic image, simultaneously adding ambient, dance, and electronica touches on 1991's ACHTUNG BABY. Mining that vein for much of the decade, U2 kicked off the 21st century with a triumphant return to form that was embraced by new and longtime fans alike.