Metal-punk weirdos the Melvins are on the road to celebrate the fact that they’ve been a band for thirty years. Since forming in Montesano, Washington in 1983, the band has released twenty albums, including a few on the major label Atlantic Records, but its sludgy, experimental sound has kept it mostly underground. Musicians have consistently cited the Melvins as a huge influence, including Nirvana bassist Krist Novoselic, who wrote in a Seattle Weekly column that they were “the first Grunge band.” (Melvins’ drummer Dale Crover briefly played drums with Nirvana.) For the band’s thirtieth anniversary tour — which will stop by Slim’s (333 11th St., San Francisco) this week — core members Crover and singer/guitarist Buzz Osborne (aka King Buzzo) will be joined by second drummer Coady Willis and ex-Butthole Surfers bassist Jeff Pinkus. Reviews from the 38-show tour have been glowing, reporting a set list filled with highlights from the band’s career played in its signature style — loud, aggressive, and playful.