After high school, Gabrels attended the Parsons School of Design and the School of Visual Arts in New York City but continued to play guitar. Through some session musician work he met noted jazz guitarist John Scofield, from whom he took a lesson or two. Gabrels moved to Boston to attend the Berklee School of Music, which he left several credits short of a degree in 1981.
Gabrels was introduced to David Bowie during a Bowie tour in 1987 for which Gabrels' journalist wife, Sara Terry, worked as publicist. Gabrels later (1989-1993) joined forces with Bowie and the Sales brothers (drummer Hunt Sales and bass player Tony Sales) in the rock band Tin Machine. Later, Gabrels became an essential part of Bowie's nineties sound, most notably on Outside (1995), Earthling (1997), and 'hours...' (1999), the latter two of which he co-produced. Gabrels and Bowie also created the soundtrack to the computer game Omikron: The Nomad Soul in 1999 for the game's French publisher. Gabrels ended his professional association with Bowie in late 1999.
Independent of his work with Bowie, Gabrels maintained a wide-ranging career as composer/songwriter, musical collaborator, and solo performer/producer. He worked with Robert Smith of The Cure during the 1990s, collaborating on The Cure's track "Wrong Number" and "A Sign From God" (as COGASM) as well as co-writing the song "Yesterday's Gone" which Smith sings on Gabrels' 1995 solo album Ulysses.
Gabrels has written soundtracks for films including David Sutherland's "The Farmer's Wife" (Frontline, 1995) and for PBS productions, and collaborated with Public Enemy on the song "Go Cat Go" for the Spike Lee film "He Got Game" (soundtrack, Def Jam, 1998). He wrote the "club music" portions of the soundtrack for the video game Deus Ex. Gabrels and slide guitarist David Tronzo joined forces on a virtuoso instrumental album, "Night in Amnesia," issued by Rounder in 1995.
Solo records by Gabrels include The Sacred Squall of Now (Rounder/Upstart, 1995); Ulysses (Emagine, 2000); Live, Late, Loud (Myth Music, 2003); and Rockonica (Myth Music/Favored Nations/Sony, 2005). Gabrels joined Heavy metal supergroup X-World/5 with drummer Big Swede, bass player Magnus Rosén, vocalist Nils K. Rue, and guitarist Andy LaRocque. Their album "New Universal Order" was released by German label AFM in June 2008.
Since 2006 Gabrels has been based in Nashville, Tennessee where he often performs in a trio with drummer Jeff Brown and bass player Kevin Hornback ("Reeves Gabrels and His Imaginary Friends").