John Du Prez (formerly Trevor Jones) was a Trevelyan Scholar at Christ Church, Oxford. In 1976 he joined the staff of London University's Music Department, but soon devoted himself to composition full-time.

He entered the film industry in 1978, composing additional music for Monty Python's Life of Brian. This began a 30-year association with Eric Idle. Their stage musical Spamalot has won them a Tony award for Best Musical and a Grammy award for Best Original Cast Album. 2010's Not The Messiah (He's a Very Naughty Boy) brought their work full circle to Life of Brian.

His film work continued with Monty Python's The Meaning of Life, and he then changed his name to John Du Prez in order to avoid confusion with the South African film composer Trevor Jones. Du Prez then became the trumpet player in the New Wave Salsa (termed "New Romantic") band Modern Romance, who had a hit with "Everybody Salsa" in the early 1980s. To celebrate his name change, they even created a song named after him: "Who Is John Du Prez?", which was the b-side to the group's hit "Cherry Pink and Apple Blossom White." The band enjoyed a string of UK chart hits until 1985, when Du Prez left after the band decided to change its image to long hair and leather jackets. But his love for Latin dance music can still be heard in the Tango-infused score for his next job, Once Bitten.

Du Prez was also the music arranger for Time Bandits (1981) and has scored more than 20 feature films including A Private Function, A Fish Called Wanda, UHF and Teenage Mutant Ninja Turtles I, II and III. Other Python projects include the Contractual Obligation Album, Monty Python at the Hollywood Bowl and The Fairly Incomplete & Rather Badly Illustrated Monty Python Song Book. He was also musical director for Eric Idle's two North American stage tours, Eric Idle Exploits Monty Python (2000) and The Greedy Bastard Tour (2003). Du Prez and Eric wrote and performed the song 'Really Nice Day' in the animated movie The Wild (2006). Du Prez has also collaborated with ex-Modern Romance frontman David Jaymes a number of times, most notably on the feature film Fascination (2004), and their single 'Best Years of Our Lives' featured in Shrek (2001).