Opeth is a Swedish heavy metal band that formed in 1990 in Stockholm. While the band has been through several personnel changes, singer, guitarist, and songwriter Mikael Åkerfeldt has remained Opeth's driving force since joining shortly after its inception. While firmly rooted in Scandinavian death metal, Opeth incorporates progressive metal, progressive rock, folk, blues rock and jazz into their usually lengthy songs. Many compositions include acoustic guitars and strong dynamic shifts, as well as growling and clean vocals. The band rarely played live to support the first four albums, though later conducted its first world tour after the release of 2001's Blackwater Park.   Wikipedia