Official Website: http://opeth.com/
Opeth is a progressive death metal band that exploded into the international metal scene with their album "My Arms, Your Hearse" back in 1998. They have arguably become the biggest progressive death metal band on the planet.
Opeth's distinct sound combines heavy metal with acoustic passages, while incorporating elements of progressive rock/metal and jazzy guitar solos.
Mikael Åkerfeldt is well-known for his ability to switch from clean to growling death metal vocals effortlessly with the change in intensity of every song.
Here's a Live performance of "Demon of the Fall" off their 1998 album "My Arms, Your Hearse"