Heading into Unorthodox Jukebox, Bruno Mars was already launching a total takeover of the pop planet. As a member of The Smeezingtons—a writing-production trio that also included Philip Lawrence and Ari Levine—Mars played a crucial role in the 2010 successes of CeeLo Green’s “Fuck You,” Travie McCoy’s “Billionaire,” and B.o.B.’s “Nothin’ on You.” That same year came his debut album, Doo-Wops & Hooligans, which featured the chart-topping singles “Just the Way You Are” and “Grenade.” Though only in his mid-twenties, Mars already had the kind of career year most artists would never be able to beat. Still, it wasn’t until the 2012 release of Unorthodox Jukebox that it became clear Mars had the makings of a future Super Bowl headliner. The 10-track album, clocking in at a concise 35 minutes, wasn’t just a pop blockbuster—it was a superstar-making statement. And while Unorthodox Jukebox begins and ends with the doo-wop stylings Mars employed on his debut—on “Young Girls” and “If I Knew,” respectively—the album represents a style-hopping leap forward, featuring everything from reggae-pop (the Police-indebted smash “Locked Out of Heaven”) to soul-baring balladry (the chart-topping “When I Was Your Man”) to roller-skating R&B (the sparkling “Treasure”). On Jukebox jams like “When I Was Your Man,” you can also hear Mars growing as a singer, one who’s confident enough to flex his vocals backed only by his own piano—with nowhere to hide. The album also finds Mars making some unorthodox choices with his lyrics, which are occasionally riskier (and more risqué). There’s sex, drugs, and alcohol mixing into the Princely allegories of “Gorilla” and “Moonshine,” while “Natalie” and “Money Make Her Smile” reveal the baller paranoia of a man who’s no longer the romantic innocent of his breakout single, “Just the Way You Are.”