Question: Mayhem Festival 2015 included a Danish heavy metal musician who was the lead vocalist for what non-namesake band?
Sentence (from "Mayhem Festival 2015"): It was confirmed that Slayer, King Diamond, Hellyeah and The Devil Wears Prada will be headlining the festival, while Whitechapel, Thy Art Is Murder, Jungle Rot and Sister Sin would be among those supporting.
Relevant evidence: Yes