Zoroaster

On their MySpace page, Atlanta metal-rockers Zoroaster describe themselves as sounding like “DINOSAURS TAKING A SHIT,” an unbecoming but not entirely inaccurate simile for their droning, monstrous sound. Like Zoroaster, who headline a 9 p.m. show at Vnuk’s, openers Sourvein, of North Carolina, kick up a giant racket, distorted as though the entire band were sharing one beaten, oversized amp they picked up at a rummage sale. Also on the bill is Ganon, a Michigan group that bridges the indie/metal divide with gorgeous, post-rock-influenced passages and unforgiving, Black Sabbath-sized riffs.