Davies' most famous association was with Britten, whose War Requiem he premiered in 1962 at the new Coventry Cathedral.

He began as organist and director of music at the St. Albans and Hereford cathedrals, and went on to conduct, among other ensembles, the City of Birmingham Choir, the Birmingham City Orchestra, the English Opera Group, the Vancouver Symphony Orhestra, the BBC Training Orchestra, and the Royal Choral Society.

Davies also made guest-conductor appearances at Covent Garden and Sadler's Wells, and appeared frequently at the Cheltenham festival as well as at Aldeburgh.

He was also active in music education, as principal of the Trinity College of Muisc from 1979 to 1988 and with the London Schools Symphony Orchestra.