sentences:  He was appointed professor of violin at the RCM at the age of 24 and became a freelance London orchestral player, until he was made sub-leader and then leader (1956–67) of the Philharmonia Orchestra.He was co-leader of the BBC Symphony Orchestra from 1967 to 1969, when he resigned to concentrate on an independent career, but retained his membership (1966–76) of the Music Group of London.In 1989, he returned to the Philharmonia Orchestra as co-leader, and became Leader Emeritus.