Black Pus is Brian Chippendale’s personal pugilistic playground, a realm where the Lightning Bolt drummer gets to let his freak flag fly long, hard, and largely unedited: he mashes skins, strings, and keyboards into a noxious paste as aurally repulsive as its namesake. On Primordial Pus, as with 2008’s Black Pus 4, his impromptu shotgun marriages of steamrolling slam and sucker-punching melody invigorate. But Primordial Pus is both the first Pus disc that isn’t self-released and the project’s most sonically trenchant. Its thudding bass whumps and stickwork show immensely terrestrial, undertow strength. On “Hole In The Ground,” a cartoonish, close-mic’d vocal bears the hook as gnashing instruments and no-fi atmospherics carve a scraped, squeaking backdrop, while caveman-stomp “Police Song” is almost frat-paddle infectious, its rampaging nonsense-syllable chants as relentless as its drumbeats. And there’s something poetic — existential, even — about the Herculean exertions displayed on “Ha Ha Havok,” where Chippendale sounds like a six-armed colossus struggling to punch and kick his way out of a reinforced steel cube. Piqued and primal, Primordial Pus finds Chippendale as manic and gnarly as ever — no small feat at a point in his project’s career where most thrashers would’ve gone hi-fi and mellowed out.