Born in London in 1947, Guy first came to prominence in the '60s as a member of pianist Howard Riley's trio alongside drummer Tony Oxley, appearing on albums like 1967's Discussions, 1969's Angle, and 1971's Flight. In the early '70s, Guy formed the innovative London Jazz Composers Orchestra, a collection of like-minded artists that included such luminaries of the British avant-garde jazz scene as Evan Parker, Paul Lytton, Derek Bailey, Paul Rutherford, Karl Jenkins, and many more. The group debuted with a recording of Guy's long-form composition Ode in 1972. Also during this period, he appeared on albums with Riley, John Stevens, Bob Downes, and others.
Guy's second album with the London Jazz Composers Orchestra, Stringer, appeared in 1984. Harmos followed in 1989. The '80s also found him working regularly with fellow LJCO members saxophonist Parker and drummer Lytton. Together they released such albums as Pisa 1980: Improvisor's Symposium and 1986's Atlanta.
The '90s were a prolific decade for the bassist, who appeared on numerous albums with the London Jazz Composers Orchestra, including 1990's Double Trouble, 1991's Theoria, 1993's Portraits, and 1995's Double Trouble Two. He also delivered a handful of well-received solo efforts: 1991's Fizzles, 1993's After the Rain, 1995's Sensology (with Paul Plimley), and 1997's Gudira. His contributions to other artists' albums also increased, with appearances on albums by Cecil Taylor, Bill Dixon, Mario Schiano, and others.
Guy's output continued to increase over the next several years, showcasing more collaborations with Parker and Riley, as well as with pianist Marilyn Crispell, saxophonist Mats Gustafsson, pianist Sten Sandell, and others. In 2006, he reconvened the London Jazz Composers Orchestra for Dance for Human Folks. Also that year, he released the solo album Folio, followed a year later by Zafiro. In 2010, he paired with trumpeter Peter Evans on Scenes in the House of Music. Two years later, he joined Ian Whitcomb for Songs Without Words and in 2014 he collaborated with Fred Frith for Backscatter Bright Blue. In 2016, Guy appeared on several albums including Deep Memory with Crispell, as well as his own The Blue Shroud, featuring his Blue Shroud Band. He then paired with trumpeter Peter Evans for 2018's Syllogistic Moments. ~ Matt Collar, Rovi