SunnO))) is quite something. Greg Anderson and Stephen O'Malley, two bearded guitarists who wear monks' robes and play at the approximate rate of one chord every 30 seconds, have ritualized the most potent aspects of heavy-metal loudness and boredom into a kind of vibrational black Mass. Monday night at the Middle East Upstairs, a sold-out crowd voluntarily underwent something approaching a musical purge, with volume pushed to the edge of numbness and pleasure abolished.
Taking their name from the Sunn Model T amplification they use (apparently that O))) is silent) and their concept from '90s slo-metal originators Earth, Anderson and O'Malley summon a monstrous drone, a leviathan snoring, and then hold it until you beg for mercy. A vocalist in black-and-white face paint appeared and screamed fitfully, and there was a third hooded person doing something to a keyboard, but it was the guitars, the huge, excruciatingly sustained chords, that drove this bowel-shuddering sabbath.
A SunnO))) show is by no means a good time. The volume is tremendous, troubling, rattling the glasses on the bar and turning earplugs into miniature woofers. Floorboards quake; a peculiar hunted expression is seen on many faces in the crowd. Beneath such pressure the mind oscillates wildly. Reject the whole experience? Submit to it? Intellectually, SunnO))) is preposterous -- the robes, the beards, the gormless musical fixation.
But at an organic level -- and it is the organs, rumbling in their nests of anatomy, that respond most sincerely to the SunnO))) shock wave -- it is astonishing. And it's heartening to reflect that on a frigid weeknight in the holiday season, at an hour when they should have been in bed, there were people lining up gladly to receive this super-slow sonic mauling.
For an encore, SunnO))) delighted local fans with a surprise cover of the Cars' ''Just What I Needed," throwing back their hoods to reveal grinning faces. . . . No, they didn't. They stuck to the script, cut the sound abruptly, and left their audience in a harrowed, throbbing silence. Merry Christmas!