Downes was noted for his championing of British music, and especially for Prokofiev and Verdi. He advocated the symphonies of George Lloyd (also conducting a radio performance of "John Socman") and premiered works by Alan Bush, Peter Maxwell Davies and Malcolm Arnold. His passion for Prokofiev was felt in performances of both major and lesser-known Prokofiev scores throughout the world. He also conducted the UK première of "War and Peace" at a concert performance at Leeds Town Hall in 1967. In 1979 he completed the orchestration of a one-act Prokofiev opera, "Maddalena"; he conducted its first recording in 1979 and its world premiere staging in 1981.