Defensive celebrity rants don’t come more fun-loving than this R&B hottie’s bouncy new cut ”Pop Ya Collar” — named after a shirt-tugging gesture signifying self-assurance and cool. Over an airy electro groove by producer Shek’spear (”No Scrubs”), the self-described ”king of hip-pop” rousingly rails against jealous types who resent his success — on the charts and with the ladies. An anthem for the playa within. B+