Hot Song: Justin Bieber's 'Boyfriend'

Justin Bieber isn't going to have any growing pains. His new single, "Boyfriend" (Island Def Jam), finds The Bieb stepping into a more grown-up role with ease, following Justin Timberlake's R&B-loving lead without losing his own identity. (Don't the verses have a tinge of Bieber fave "Teach Me How to Dougie"?) The clever production of Mike Posner smooths out Bieber's vocals, while stripping nearly everything else away so that they still shine in the spotlight. "Boyfriend" should be a "Baby"-sized smash.