We're not sure how they do things in Canada, but here we are a nation of laws, and this is one of them: When you make your first rap song about how good your penis tastes, make it one to remember. But if this jam with MCs Juicy J and Maejor Ali is pro forma, Biebs acquits himself reasonably well with chest-hair-poppin' flow and verses more cute than cringe-inducing: "Got your girlfriend at my crib watching Netflix/Let's just admit that I'm the bestest." One to grow on.

“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."