With factions of the hip-hop underground thinning out its beats until they’re as vestigial as folkie hand claps around the campfire and suckers like Anticon’s Sole claiming “I only rap because I ain’t smart enough to write a book,” you’ve got to wonder about indie rap’s priorities. No less wordy than his peers, Long Island-born MC Ian Bavitz, aka Aesop Rock, probably is smart enough to write a book but understands that lines like “Running from a rabid Ringwraith / Fling basilisks / Serpentine / In and out of traffic jams and murder scenes” would lose all immediacy (if not comprehensibility) without the dubwise snare pattern stuttering beneath him. Released on Definitive Jux in 2001, Labor Days is still the most fully realized example of that label’s claustrophobic aesthetic–not just words spilling recklessly past metric constraints, but rhythm tracks that stagger home around dawn, with a swollen bass gulped down through the drums. Similarly there’s nothing you can dance to on the new Bazooka Tooth (unless someone’s tied your shoelaces together), but from the pots and pans clattering through the title track to the belly-dancing whirl of “N.Y. Electric,” this is hardly just glorified beat poetry. While the sexy faux-pimp fable “Cook It Up” and the urban vignette cycle “11:35” show off Ace’s keen if somewhat undisciplined sense of narrative, his strength remains the snazzy dis, whether targeted generally toward unnamed foes (“You should’ve shot yourself in the foot when it was in your mouth”) or specifically at pseudoreligious gangstas (“I hear He overlooks manslaughter for a tattooed crucifix”). Bazooka Tooth never peaks as high as Labor Days, but when an MC can indulge in the standard-issue I-was-here-first claims of “We’re Famous” (a duet with Def Jux honcho El-P) without sounding petty, he’s on some kind of a roll. Thursday, September 25, 6 PM, Bottom Lounge, 3206 N. Wilton; 773-975-0505.