After splitting for five years, London's Part Chimp decided to play a few shows in 2016, and they liked it enough that they chose to make it official and cut a new studio album. Part Chimp's 2017 reunion effort is called IV, since it's their fourth studio LP, and if that suggests the band is picking up where they left off, it's not far from the truth. But where most bands who get back together sound a bit half-hearted when they cut new material, that's not at all the case here. IV is gloriously, monolithically loud, and is certainly on a par with the band's best work from their first era. If there's a bit less Sonic Youth-influenced noise in the mix on IV, the band's heavy factor has increased to compensate, and guitarists Tim Cedar and Iain Hinchliffe here unleash a wailing wall of Iommian distortion that makes Sleep's Dopesmoker sound like jangle pop. By any musical standard, IV sounds huge, and the full-on brontosaurus stomp of this music will either club you into submission or leave you begging for more. Cedar and Hinchliffe are certainly lucky to have a rhythm section that can live up to their heavyweight standards, and drummer Jon Hamilton and bassist Joe McLaughlin more than rise to the occasion; this foursome delivers a gumbo of hard rock, grunge, noise rock, metal, and pure and simple aural assault that burns gloriously. IV is strong stuff, but if you wonder if Part Chimp have lost their touch after half-a-decade out of the game, this music provides a conclusive answer: not even a tiny bit.