The first musical work for which is he remembered was his role as bassist in the trio Joseph Holbrooke, alongside Derek Bailey and Tony Oxley. The trio began by playing relatively traditional jazz before moving into free improvisation. However, Bryars became dissatified with this when he saw a young bassist play in a manner which seemed to him to be artificial, and he became interested in composition instead.
Bryars' first works as a composer owe much to the so-called New York School of John Cage (with whom he briefly studied), Morton Feldman, Earle Brown and minimalism. His first known work as a composer, The Sinking of the Titanic (1969), is quite an indeterministic work which allows the performers to take a number of sound sources related to the sinking of the Titanic and make them into a piece of music. Another well known early work is Jesus' Blood Never Failed Me Yet (1971), which has at its basis a recorded loop of a tramp singing the hymn of that name. On top of that loop, rich harmonies played by a live ensemble are built, always increasing in density, before the whole thing gradually fades out. A recording of this work was made in the 1990s with Tom Waits singing along with the original recording of the tramp during the final section.
Bryars was also involved around this time with the Portsmouth Sinfonia, an ensemble which was made up of performers of all musical abilities which played (or attempted to play) popular classical works.
Bryars' later works have included A Man In A Room, Gambling, which was written on a commission from BBC Radio 3 and Artangel. Bryars' music is heard beneath monologues spoken by the Spanish artist Juan Muņoz, who talks about methods of cheating at card games. The ten short works were played on Radio 3 without any introductory announcements, and Bryars is quoted as saying that he hoped they would appear to the listener in a similar way to the shipping forecast, both mysterious and accepted without question.
Bryars has written a large number of other works, including three operas, and a number of instrumental pieces, among them three string quartets and several concertos. He has written several pieces for choreographers, including Biped for Merce Cunningham.
Bryars founded the music department at Leicester Polytechnic (now De Montfort University), and taught there for a number of years. He lives in England, and, in the summer months, on the west coast of Canada.