Question: Sanrabb is one of the founding members of which extreme subgenre of heavy metal music?
Related documents: [0]  [DOC] Black metal is an extreme subgenre of heavy metal music. Common traits include fast tempos, a shrieking vocal style, heavily distorted guitars played with tremolo picking, raw (lo-fi) recording, unconventional song structures, and an emphasis on atmosphere. Artists often appear in corpse paint and adopt pseudonyms. [END] 
[1]  [DOC] Sanrabb is a Norwegian black metal musician and one of the founding members of black/death metal band Gehenna. [END] 
Answer: 
Black metal
Black metal