Born in Detroit, Gregory first gained national prominence when he joined Arizona thrash-metalists Flotsam & Jetsam as bassist in 1987, a year after Jason Newsted left the group to join Metallica. In 1991, Gregory left Flotsam & Jetsam and joined New York art thrash band Prong in time to work on their album Prove You Wrong. Gregory's stay with Prong proved to be short-lived, and after working with the likes of the Swans, Killing Joke, and Simon Bonney, Gregory relocated back to Detroit, where he immersed himself in the local underground music scene.

Gregory formed the Witches with a rotating lineup of players from some of Detroit's more notable bands and recorded their first album in 1996, Everything Changes Reality, which sadly was never released. The Witches' second album, Let's Go to the No Go Zone, met a happier fate, hitting record stores in 1998; at this point, Gregory's collaborators included Matthew Smith (Outrageous Cherry, Volebeats), Deb Agolli (Outrageous Cherry), and Jim Diamond (Dirtbombs). A third album, Universal Mall, followed in 2001, which included members of the Wildbunch and the Sights. When not busy with the Witches, Gregory pursued an interest in filmmaking and collaborated with a variety of other Motor City musicians, contributing to projects by artists as diverse as Andre Williams, Larval, Medusa Cyclone, and Kim Fowley.

After the release of the Witches' 2002 album On Parade, Gregory joined the Dirtbombs. This move effectively meant he had less and less time to spend on the band and the next album didn't appear until 2006. Thriller! was the group's last album. Gregory maintained a steady presence on the Detroit rock scene and in 2011, the Witches' short but influential career was commemorated by the release of a career-spanning collection, A Haunted Person’s Guide to the Witches, on Alive Records. ~ Mark Deming & Tim Sendra