T-Pain tunes: perfect for lap dances, and sur- prisingly good for extended listening. Still leaning hard on Auto-Tune, Pain concocts song titles to rival R. Kelly and backs them up with slow-jam indulgences testifying to a life of unfettered pleasure. (The piano-accented "Rock Bottom" doesn’t concern an alcoholic's ultimate low; it’s about a sexual position.) In T-Pain's world, ethnicities blur ("Mix'd Girl"), rosé pairs nicely with top-shelf tequila ("Bottlez") and happy hour arrives in the morning (minor hit "5 O'Clock," featuring a deadpan Lily Allen). It gives credit to his cheerily assured worldview that Pain's roboto soul sounds like inspiration.

Listen To "5 O'Clock":

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“I'm Yours”

Jason Mraz re-emerged after his disappointing second album with this lead single, a Jack Johnson-esque ditty about giving yourself fully to someone else. The success of the reggae-tinged song (it earned two Grammy nods and a spot on the Billboard singles chart for well over a year) was something the folk-pop singer never predicted when he wrote it in 15 minutes at home. "I played a happy-hippie chord progression that would probably work without 50 different Bob Marley songs," he told Rolling Stone. "I thought, 'It's too novelty. This is a nursery rhyme,'" concluding that "you can never guess what's gonna be a hit."