There are at least 5 artists under this name. Two Black Metal Bands, a Hardcore Punk Band and a Electronica Musician with this Nickname:

#1) Mayhem is a Norwegian black metal band which was originally formed in 1983, taking strong influence especially from Hellhammer/Celtic Frost, Venom and from earlier Bathory. The band's initial line-up consisted of Manheim on drums, Necrobutcher on bass guitar and Euronymous on guitar. The name "Mayhem" was taken from the title of the Venom song "Mayhem With Mercy". Much controversy has surrounded the band regarding various murders, suicides, and other forms of violence. Mayhem have moved through a variety of black metal styles, even going so far as delving into the areas of dark avant-garde industrial and electronica. The group (at least in its earliest incarnation; 1983-1993) are widely considered to be one of the cornerstone bands in the movement often labelled "the second wave" of black metal. In the years since, their influence has only grown.

By April 1991, Dead was dead, aged 22, having suffered a self-inflicted shotgun wound to the head and several lacerations to the wrists, inflicted by a hunting knife he had bought that day. Dead committed suicide in a house he was sharing in Kråkstad with the other members of the band, and left a note asking that they "Excuse all the blood, Cheers." although other members of the band claimed it was more extensive, it also said "the knife was to dull to finish the job so i had to use the shotgun" Euronymous was first to discover the body, and took a series of polaroids of the corpse, some of which were later used as cover art for the bootleg album, "Dawn of the Black Hearts".

According to Occultus, who briefly took position as vocalist after Dead's suicide: "He (Dead) didn't see himself as human; he saw himself as a creature from another world. He said he had many visions that his blood has frozen in his veins, that he was dead. That is the reason he took that name. He knew he would die.."

The bullets used had been sent to him by Bergen, Norway musician Kristian Vikernes (aka Varg Vikernes, Count Grishnackh; ex Old Funeral, sole member of black metal band Burzum, later convicted murderer of Euronymous). Euronymous was particularly cold and opportunistic about Dead's suicide; in interviews he claimed, speciously, that Dead had killed himself due to the rising popularity of death metal, the American movement Black Metal had risen against. According to Hellhammer, Euronymous took pieces of Dead's brain and made a stew, in which he put ham, frozen vegetables, and pepper. "He'd always said he wanted to eat flesh, so he figured this was an easy way." Still, Euronymous admitted later on in an interview, that he did not actually do it. Euronymous also claimed to have collected and forged fragments of Dead's skull into necklaces, sending pieces to those he felt 'worthy' (amongst those rumoured to be in possession of such pieces are the members of Swedish black metal band Marduk). Hellhammer has said he made a necklace from Dead's skull fragments as well.

#2) Mayhem is an electronica producer from the US whose music includes various styles, such as jungle, hardcore, drum & bass, and house.

#3) A Hardcore Punk Band that released just one 7 Inch Vinyl (7") called "GENTLE MURDER" in 1982.

#4) A black metal band from Japan with a six track demo released in 1985.

#5) A hungarian Venom-like pre-black/thrash metal band released one demo in 1989.