"Boyfriend" Justin Bieber

There comes a stage in the career of every teenage pop star when it's time to "grow up." It's a tricky transition from bubblegum youth to adult acceptance, and previous aspirants have seen varied results, from some of the most successful recording careers of all time (Michael Jackson, Britney Spears) to has-been punchline status (Miley Cyrus). Thus arrives the moment of truth for tween sensation Justin Bieber, who turned 18 earlier this month; new single "Boyfriend" is a swaggering hip-hop track that aims to bolster his urban appeal and cool factor. The ploy may work—at least, for the lovestruck middle schoolers that have converted everything he touches into multi-platinum. For the rest of us, the thought of the Biebs as a whisper-rapping Casanova who wants to "make you shine bright/like you're laying in the snow" (I don't know what that means, but it sounds gross) is more than a little unsettling. And yet...that chorus—from the falsetto bridge to the acoustic guitar hook—is simply too catchy to completely dismiss the song. Let's just the split difference and call it a B-.