“Number One Spot,” the lead-off track from Ludacris’ fourth album, The Red Light District, shows that the Atlanta radio DJ-turned-rapper has more fun in one four-minute single than most contemporary rappers allow themselves in their entire career. As DJ Green Lantern slices and dices Quincy Jones’ “Soul Bossa Nova,” Luda unleashes a tornado of put-downs, boasts, and in-jokes all filtered through the prism of Austin Powers. It’s an amazing, if unrepentantly goofy, display of rap craftsmanship. Add to that the hypnotic weed rap of “Blueberry Yum Yum,” and the vertiginous Timbaland production “The Potion” and there is a strong case to be made for The Red Light District as Luda’s psychedelic record. Still, the lowrider thump of “Spur of the Moment” and “Child of the Night” display an undying love for West Coast rap, while “Pimpin’ All Over the World,” “Hopeless,” and the Curtis Mayfield-sampling “Two Miles An Hour” prove the Atlanta rapper’s unparalleled taste in vintage soul.