Melvins are an American rock band formed in 1983 in Montesano, Washington. Known for combining heavy, slow riffs with experimental and eclectic songwriting, the band has been credited as pioneers of sludge metal, and a key influence in the development of alternative metal and grunge. Since 1984, vocalist/guitarist Buzz Osborne and drummer Dale Crover have been the band's only constant members. Primarily a trio, they have also performed as a quartet, with either two drummers or two bassists, and have been credited for their prolific output, having released over 25 studio albums.