Add this Atlanta native to the list of the year’s most notable hip-hop newcomers. Ludacris’s debut, Back for the First Time, is a randy charmer largely because of the contrast between his dirty, down-home raps and the sleek future-shock beats of producers like Timbaland and the Neptunes. A remix of his smash ”What’s Your Fantasy,” containing a thrillingly crass verse by Foxy Brown, boosts the album’s potent, hardcore sex appeal. B+