Anderson is the guitarist in the doom/stoner metal outfit Goatsnake, but is also well known for his collaborations with Stephen O'Malley. Together they have participated in projects such as the short-lived death/doom metal band Thorr's Hammer, the extreme doom metal band Burning Witch (although Anderson left before the band could record an album), as well as the drone doom metal bands Sunn O))) and Teeth of Lions Rule the Divine.
Earlier in his career, Anderson was involved with the straight edge hardcore punk bands: False Liberty, Brotherhood, Amenity, Statement, Galleon's Lap and the Revelation Records, indie rock/hardcore punk band, Engine Kid.
Recently, Greg has joined Attila Csihar and Oren Ambarchi in a new drone doom project called Burial Chamber Trio, as well as Ascend, a current project/record with Gentry Densley, the former singer/guitarist of Revelation Records band, Iceburn.
In April 1998, Anderson and O'Malley founded the independent, underground label Southern Lord Records, based in Los Angeles, California. The company specializes in doom, sludge, drone, experimental metal, and more recently left-field black metal.