He exposed medicine in London, but got pursued a learn of music from an early age. He exposed composition with Alan Rawsthorne and Patrick Hadley. His virtually all successful early works involved the setting of T. S. Eliot's The Hollow Men (1939), several ballets, including A Mirror for Witches (1952) and Blood Wedding (1953), and an opera, Yerma (1954). About 1960, he began composing in the serialist style, and this continued until a late 1980s, after he returned to diatonic composition.

ApIvor is particularly easily-known to guitarists, as he manufactured the major contribution to the repertoire of their instrument. Solo works include Variations (1959), Discanti (1970), Saeta (1972) and Tenner serial pieces involved using his book Serial Composition for Guitar player (1982). He too wrote the Concertino for guitar (1954), Liaison for guitar and keyboard (1976) and Cinquefoil for flute, guitar & viola (1984).