Achtung Baby (1991) is the album on which U2 stopped being the earnest, flag-waving champions of the 1980s and became something far more interesting: a flawed, horny, paranoid band that sounded like it might actually break up. Recorded in a divided Berlin still echoing with the fall of the Wall, the record captures four men confronting middle age, failing marriages, and the terror of becoming their own tribute act. The result is their masterpiece.

Gone is the clean, ringing guitar of The Edge; in its place are squalls of distortion, drum machines, and loops that owe as much to industrial dance floors as to rock tradition. “The Fly” opens the album like a punch in the chest—Bono sneering through a vocoder, Edge’s riff slicing like broken glass—while “Even Better Than the Real Thing” turns media cynicism into a sleazy, irresistible strut. Yet the emotional center is quieter. “One” is the greatest song U2 ever wrote: a slow, bruised piano ballad that somehow became an arena anthem without losing its ache. “Mysterious Ways” rides a fat funk bass line into pure erotic joy, and “Until the End of the World” stages Judas’s betrayal as a late-night bar conversation you wish you hadn’t overheard.

Bono’s lyrics are newly adult—jealous, petty, tender, cruel. “So Cruel” and “Love Is Blindness” dissect a collapsing relationship with a candor that would have been unthinkable on The Joshua Tree. The production, shaped by Brian Eno and Daniel Lanois, wraps these confessions in glamorous noise: reverb-soaked guitars, backwards vocals, and a sense that the band is testing how much abrasion an audience will still dance to.

Achtung Baby didn’t just save U2; it redefined them. It proved they could be ironic and sincere at the same time, that stadium rock could also be art. Thirty-five years later it still feels dangerous—sexy, funny, and heartbroken in equal measure. For a band once accused of terminal earnestness, few records have sounded this alive.