It was on this date, 30 years ago, that the Clash's London Calling was first released in the U.S. Three decades on, it remains an indisputable masterpiece. After all, the British band's third (and best) album is a time capsule pinpointing the exact moment when punk rock grew up. While other bands like the Sex Pistols captured the f-you rebellion and catharsis of punk, the Clash on London Calling aimed higher. Anything was possible when they stepped inside the studio with producer Guy Stevens. The band fearlessly experimented with ska, reggae, and rockabilly beats. And Strummer's lyrics took on a new political urgency. London Calling was proof that what some regarded as a gutter genre could be sophisticated and smart. In short, that it could be art. With classic tracks like "Spanish Bombs," "Lost in the Supermarket," "Clampdown," "Train in Vain," "Guns of Brixton," and, of course, the call-to-arms title song, London Calling was a vinyl-pressed molotov cocktail. In fact, in 2004, we here at EW named it "The Best Album of All Time."