Question: In what year was the heavy metal band from Tronheim, Norway, who specializes in music that embodies a continuous move between explicit and implicit references to genres and strategies derived from cultural domains, formed?
Sentence (from "Darkthrone"): In 1991, the band embraced a black metal style influenced by Bathory and Celtic Frost and became one of the leading bands in the Norwegian black metal scene.
Relevant evidence: No