Oliver's father Henry Whitehead was a mathematician at Balliol College, Oxford, and a codebreaker at Bletchley Park during World War II.

His mother Barbara began a career as a concert pianist (under her maiden name Smyth), but spent most of the 1950s and 60s running a farm that the family bought in the tiny village of Noke, near Oxford.

Instead, Oliver taught himself guitar and, by means of the radio and his wind-up 78 rpm gramophone, soon discovered all the British chart-toppers of the day, such as Tommy Steele, Lonnie Donegan and Cliff Richard, later finding more advanced models in Andres Segovia and Django Reinhardt.

After his father's early death in 1959, when Oliver was 11, his mother increasingly spent time in Donegal, Ireland, where she had holidayed as a child, eventually moving there permanently in 1970.

The only guitar lesson Oliver ever took was from Julian Bream, who showed him a few blues and jazz licks, during a Christmas party with Britten and Pears in 1962.

The key players in that work went on to form The Antler River Project, which continues to play original jazz/world music compositions by Whitehead and pianist Steve Holowitz.

That oratorio is based on the book Cosmic Consciousness by Richard Maurice Bucke, an early 20th-century psychiatrist and mystic who lived in London, Ontario.

The field of Comparative Literature allowed him the freedom to break traditional academic boundaries by incorporating all the art forms, especially music, in his courses.