A key measure of a hip-hop album's effectiveness is the level of envy it evokes. At the least, listeners should come away impressed by the rapper's dexterity and moxie behind the microphone; at the most, they should wish for even a fraction of his or her lyrical skills. Spank Rock a Baltimore-based duo consisting of rhymer Naeem Juwan and producer Alex Epton frustrates this maxim with YoYoYoYoYo in large part because Epton's deft, skeletal beatmaking far outshines Juwan's charmless, oversexed after-party raps and stale thug boasts. Epton appoints "What It Look Like" with an anxious latticework of string plucks and arrhythmic beat crunches that render Juwan's slippery doggerel a labored non sequitur. Likewise "Chilly Will" appeals less in its passionless, Pharrell-ish come-ons than the song's dual framework, an arctic pulse of finger snaps, timpani, and bass that breaks into a funk groove reminiscent of the Chemical Brothers live. Guest star Amanda Blank out-sasses Juwan at his own triple-X game on "Bump," a track that apes the rhythm of Tone Loc's "Wild Thing" where Juwan's flow mirrors Eminem's circa the ultramisogynistic "Superman." Spank Rock is a match made in sort of b-boy purgatory.