The British jazz composer and bandleader Mike Westbrook, a restless innovator who helped redefine the scope of large-ensemble jazz in the UK, has died aged 90.

Born in High Wycombe and raised in Torquay, Westbrook came to music by an indirect route, studying painting in Plymouth after a stint in accountancy and National Service. It was there, in the late 1950s, that he formed his first bands, drawing around him future leading figures of British jazz including John Surman and Keith Rowe.