Coaxed to Berlin by producer Brian Eno, U2 spent several chilly months arguing over how they wanted to sound in their second decade. Larry Mullen Jr. and Adam Clayton were in the ‘Ain’t broke, don’t fix it’ camp while Bono and The Edge campaigned for changing everything. The final product is less a revolution than a reformation; the grand guitar hooks are still there, but they’re buried under polyrhythms and effects borrowed from electronic music. The songs seldom start and end at the same pace; they require more attention, and reward it, too. Bono veers between his love of sinners and saints, but his lyrics make sure it’s a fair fight, as proven by “One,” a song so accessible that it started as a bitter take on Bono’s relationship with his father, twisted into a commentary on the state of the band, became a staple at weddings and now is used as an anthem to fight global poverty.