just to add about Dead and Mayhem 
Dead was a Swede
previously from the band Morbid. He was strongly fascinated (as
his stage name indicates) by death, decay, and darkness. Even
Euronymous described
Dead as mentally unstable
and possibly schizophrenic. Dead became well known for his strange
behavior: he buried a set of clothes for months underground so that
he could wear decaying rags onstage at Mayhem shows. He also kept a rotting
raven in a plastic bag so that he could "inhale the scent of death"
before each song he performed.
In 1991, Dead committed
suicide by means of a shotgun blast to the head (he had also slit
his wrists several times). The bullets which he used had been sent
to him by Count Grishnackh
(the sole member of the black metal band Burzum and the man who later killed
Euronymous), who
apparently thought this was cool but denied having any advance
knowledge of the suicide. Dead's body was discovered, along with
a suicide note reading "Excuse all the blood", in a back room of
the band's house (this statement in the note is ironic considering
he was often accused of being humorless). Euronymous quickly took pictures
(which later appeared in the booklets for several subsequent Mayhem
releases and other bands' materials) of the bloody scene using a
polaroid camera. Persistent rumors assert that he then cooked and
ate pieces of Dead's
brain, and that fragments of Dead's skull were collected and forged
into necklaces by both Euronymous and Hellhammer
