On their new live album, released this week, Melvins sound like a slow-motion avalanche, with rumbling bass and grunge-metal guitar slamming headlong into a thicket of dueling drum sets. When the Washington state band started in 1983, they were a trio that evolved away from hardcore punk tempos into a swampy morass of Black Sabbath/Flipper/Black Flag–style riffs, a weirdly compelling blend that would directly influence their friends Nirvana, Tool and Green River. Now Melvins are even louder and fuller as a quartet, with recent additions Coady Willis (drums) and Jared Warren (bass) fleshing out the thick, languorously noisy grooves of longtime members Buzz Osborne (guitar, vocals) and Dale Crover (drums). Osborne is more of a bellower than a crooner, and the rest of the group kicks up a suitably monstrous racket to accompany his cryptically foreboding utterances on “Rat Faced Granny” and “Civilized Worm.” Crover and Willis exchange relatively brief drum solos before those thunderous riffs start to collapse again around them, leading to extended passages that move from punk and metal to stranger art-rock and prog interludes. Apart from a gratuitous, buffoonish a cappella version of “The Star-Spangled Banner,” the live album (recorded at a seemingly mythical venue in Downey called “the Busta-Guts Club”) is satisfyingly heavy and menacing.