Raging rats in rattling cages? Surgical sound pollution? Bring it on, say San Francisco electronic duo Matmos -- it's all grist for the mill of appropriated aural byproducts they operate. Their most collaborative, conceptual, and spirited full-length to date, The Rose Has Teeth in the Mouth of a Beast consists of 10 salutes to unknown or infamous underground figures. The most confrontational and eyebrow-raising of these is "Tract for Valerie Solanas," where women read charged excerpts from the would-be Andy Warhol assassin and radical feminist's S.C.U.M. Manifesto -- "it remains to civil-minded, responsible, thrill-seeking females only to overthrow the government, eliminate the money system, institute complete automation, and destroy the male sex" -- against an unsettling, emasculating ensemble of vacuum cleaners, bovine reproductive organs played like kazoos, rape alarms repurposed to whine like vintage Dr. Dre productions, and chilling metal-on-metal percussion crafted using knives, scissors, and machetes. "Rag for William S. Burroughs" pairs an archaic, old-timey piano shuffle with the outmoded creak and clatter of typewriters, film projectors, marbles, and, amusingly, Burroughs' adding machines, invented by the late Beat writer's grandfather; on "Germs Burn for Darby Crash," the sizzle of burnt skin and the resulting outcry, the hum of electric hair clippers, and an ARP 2600 are alchemized into scrambling, droning glitch. Teeth is that rare work that functions equally well as entertainment and cultural commentary, fine cuisine for mind and body alike.