Top-flight UK rapper Stormzy drops off a smooth one for the “Birthday Girl.” Master class. Stormzy is one of the UK guys who’s getting too big to be ignored in the US. Part of the reason for his ascent is that he goes far beyond the traditional heavy club sound of grime, though he’s as hard as they come when it comes to tearing up a soundsystem. Just as is requisite for the top rappers over here, Stormzy’s got different styles for different days. His latest track, “Birthday Girl,” is at once charming and wistful; a proper after hours selection for the dance floor, but there might be a few teary eyes in the crowd — especially dem girls without a man like Stormzy. He delicately raps out a heartfelt birthday message to his girl, who may not be in the best of spirits in his absence. She’s gotta forgive him after this. In any case, one can feel that Stormzy would be there if he could, were he not busy being an international MC. “Birthday Girl” is produced by Sons of Sonix