Though the rock songs on 1967’s The Who Sell Out had done well, Pete Townshend was increasingly bored by the idea of being a singles band—by making records just meant to earn radio play. Before that record’s release, he’d started to absorb the teachings of Indian spiritual leader Meher Baba, whose classic God Speaks Townshend read after a friend told him that many of Baba’s teachings foreshadowed several of the songwriter’s own ideas. “Each theory that I had expounded, many to do with reincarnation and its inevitability when considered in the light of law of averages, were summed up in one sentence,” Townshend eventually wrote in Rolling Stone. “What was so sneaky about the whole affair was the way Baba crept into my life.” And, of course, his art. Townshend soon began devising a story of spiritual evolution, about a kid coming out of tough domestic circumstances in post-war Britain, only to become something of a spiritual superstar. That story would be told in 1969’s Tommy, one of rock ’n’ roll’s most accomplished early concept albums—apologies to Sgt. Pepper’s—and a fascinating, if fractured, mirror of Townshend’s own life and those of many of his rock peers. This was, as the band members admitted, Townshend’s trip—but they became fascinated by his idea, and essentially cheered him along. Tommy sprawls across four full sides, its 74 minutes and 24 overdub-heavy tracks moving from acoustic beauty to heavy soul, from Merseybeat charm to menacing proto-punk. Despite some cynical reviews, the album immediately expanded the rock lexicon and established The Who as its most audacious and eccentric big band. So much of Tommy’s staying power derives from The Who’s ability to walk the line between complicated concept and compulsive songs: Parts repeat, and the plot twists in ways that can sometimes be difficult to follow. But most of these tunes stand on their own. “Pinball Wizard” (in which Tommy’s secret talent is revealed) and “I’m Free” (in which Tommy’s quest to become a guru of sorts begins to bloom) would become two of The Who’s most enduring anthems. There’s also “Sally Simpson,” a folk-rock escapade that Crosby, Stills & Nash might have written, and “Sparks,” a prog miniature that builds to a mighty climax. Over the decades, Tommy’s scope and sound would fall in and out of favor, but the album remains an enduring affirmation that rock can serve as serious art, too—that there are brains behind the bands.