U2 is an Irish rock band.
Achtung Baby ( [ pronˈɑːktuːŋ_ˈbeɪbiː ] ) is the seventh studio album by Irish rock band U2 . Pop is the ninth studio album by Irish rock band U2 . Songs of Innocence is the thirteenth studio album by Irish rock band U2 . The Joshua Tree is the fifth studio album by Irish rock band U2 . U2 . The group 's thirteenth album , Songs of Innocence ( 2014 ) , was released at no cost through the iTunes Store , but received criticism for its automatic placement in users ' music libraries .