Following the band's Zoo TV tour, which took aim at consumerism and media overload, U2 brought those themes and the complex, futuristic sound of it's preceding album, Achtung Baby, to their somewhat illogical conclusion on Zooropa, the group's most chaotic, cutting-edge work. The monotone techno-rap "Numb" leads the way, while "Lemon" offers reminders of David Bowie's Berlin trilogy of more than a decade before. Best of all is "The Wanderer," featuring a guest vocal by country-music icon Johnny Cash. His bottomless baritone sounds bizarre over burbling synthesizers, but Bono's trenchant lyric about a postapocalyptic seeker of sensation and experience before he repents nails Cash's legend at least as well as he ever has himself.