Since the mid-1990s, Harris has worked primarily in electronic and ambient music, his main projects being Scorn and Lull.

According to AllMusic, Harris's "genre-spanning activities have done much to jar the minds, expectations, and record collections of audiences previously kept aggressively opposed.

[6] Harris replaced Napalm Death's founding member Miles "The Rat" Ratledge as drummer in 1985.

[10] As a drummer he is generally credited with popularising the blast beat, which has since become a key component of much of extreme metal and grindcore.

[12] He was contacted by John Zorn who wanted to create a new group consisting of himself, Harris and Bill Laswell on bass.

Guts of a Virgin and Buried Secrets were released by Earache Records and contained mostly short aggressive tracks reminiscent of Napalm Death with the added elements of both John Zorn's sax and Bill Laswell's bass.

Harris later recalled how the first recording session with Painkiller led directly to his departure from Napalm Death.

[citation needed] Harris founded Scorn in 1991 with Napalm Death's original bassist/lead singer Nic Bullen.

Bullen left Scorn in 1995 and Harris continued to release albums exploring dark and minimalist industrial hip-hop territory, with a focus on extremely low and loud bass frequencies.