Opeth is a heavy metal band from Stockholm, Sweden. The band name came from the word "Opet", which was the name of a city in the Wilbur Smith novel "Sunbird". Opeth play "progressive death metal" (which comes from combining "progressive rock" and "death metal"). Opeth are also influenced by progressive rock, blues rock and jazz, and their songs often have both electric and acoustic parts. Opeth went on their first world tour after the release of their album "Blackwater Park". The band's members have changed many times since Opeth started in 1990, but band member Mikael Åkerfeldt has always been present. Although he did not start the band, Åkerfeldt is the only band member to perform in every album. Opeth has released seven studio albums, two live albums, two box-sets, and two DVDs.