Stian Aarstad is a Norwegian

Norway

Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

 pianist and keyboard player best known for his five-year (1992–97) stint with the black metal

Black metal

Black metal is an extreme subgenre of heavy metal music. Common traits include fast tempos, shrieked vocals, highly distorted guitars played with tremolo picking, blast beat drumming, raw recording, and unconventional song structure....

 band Dimmu Borgir

Dimmu Borgir

Dimmu Borgir is a Norwegian black metal band from Oslo, Norway, formed in 1993. Dimmu borgir means "dark cities" or "dark castles/fortresses" in Icelandic, Faroese and Old Norse. The name is derived from a volcanic formation in Iceland, Dimmuborgir...

 during which he played keyboards

Keyboard instrument

A keyboard instrument is a musical instrument which is played using a musical keyboard. The most common of these is the piano. Other widely used keyboard instruments include organs of various types as well as other mechanical, electromechanical and electronic instruments...

 and synthesizers while engendering criticism and controversy for appearing onstage and performing in a top-hat-and-cape outfit reminiscent of Jack the Ripper

Jack the Ripper

"Jack the Ripper" is the best-known name given to an unidentified serial killer who was active in the largely impoverished areas in and around the Whitechapel district of London in 1888. The name originated in a letter, written by someone claiming to be the murderer, that was disseminated in the...

, while wearing minimal corpse makeup

Corpse paint

Corpse paint or corpsepaint is a style of black-and-white makeup, used mainly by black metal bands during live concerts and photo shoots. The makeup is used to intensify the bands' imagery of evil, inhumanity, and corpse-like decay. It is most commonly used just on the face, but also on arms and...

 and not moving or showing any emotion.
Upon joining Dimmu Borgir, he didn't listen to metal music, preferring only to listen to classical.

In 1998 to 1999, he produced a demo-EP

Vaakevandring (EP)

Vaakevandring is the first EP by Vaakevandring, it contains the original songs from their demo plus one bonus track entitled "To Find The Eternal Peace".Vaakevandring was produced by Stian Aarstad of Dimmu Borgir....

 for the unblack metal

Unblack metal

Unblack metal is a term used to describe musically black metal sounding artists whose lyrics and imagery promote Christianity. Such artists are controversial, mainly because black metal's pioneers, especially those of the Second Wave, intended to encourage hostility towards Christianity...

 band Vaakevandring

Vaakevandring

Vaakevandring is a Norwegian unblack metal band that was active from 1996 to 2001. The name in Norwegian is a reference to the resurrection of Jesus. Vaakevandring played atmospheric, epic unblack metal with keyboards and folk melodies. Their self-titled EP was produced by Stian Aarstad of Dimmu...

. In the 2000s, Aarstad had been the pianist for the band Enthral, but left his regular position during the recording of the band's third album.