George Guest was born in Bangor, Gwynedd. His father was an organist and Guest assisted him by acting as organ blower. He became a chorister at Bangor Cathedral and subsequently at Chester Cathedral, where he took organ lessons from the sub-organist, Dr. Roland Middleton. He passed the examinations for ARCO in 1940 and FRCO in 1942. By this time he had become the organist and choirmaster of Connah's Quayparish church, Flintshire. Being proud of his Welsh roots, from the 1970s onwards, Guest took a personal interest in the Cambridge University Welsh Society, sponsoring many of its events and providing a welcome face for Welsh students away from home. At the age of 18 he was called up for military service, and joined the Royal Air Force, being posted to India in 1945. On leaving the services in 1947 he took up the post of sub-organist at Chester Cathedral. The cathedral organist, Malcolm Boyle, encouraged him to apply for the organ scholarship at St John's College, Cambridge, for which he was successful. At Cambridge he studied under Robin Orr. In his final year as Organ Scholar, Robin Orr announced that he intended to retire, and the College Council offered the post to Guest.
Within five years of Guest becoming organist and choirmaster, the whole future of the choir at St. John's College came into question, with the proposed closure of the day school which provided the choristers. Guest, with the support of his predecessor, persuaded the College to fund a Choir School. Under George Guest's direction, the choir built up a formidable reputation, challenging the supremacy of the choir of King's College, Cambridge. Guest introduced a more "continental" tone into the choir, as George Malcolm was doing at Westminster Cathedral. The choir began broadcasting on the BBC in the early 1950s and started making recordings in 1958. By the time of Guest's retirement in 1991, the choir had recorded sixty LPs or CDs under his direction. The BBC has broadcast Evensong from St. John's College on every Ash Wednesday since 1972, and the Advent Carol Service each year since 1981. During George Guest's tenure, the choir undertook many overseas tours. In 1987 Guest was appointed Commander of the Order of the British Empire in the Queen's Birthday Honours. Herbert Howells and Michael Tippett are among the many composers who wrote liturgical settings for the St. John's College choir whilst George Guest was organist and choirmaster. They also include the French composer Jean Langlais, who wrote a setting of the psalm Beatus vir for the choir: a rare occurrence of a Continental composer writing for the English cathedral tradition. Organ Scholars who studied under George Guest include:
George Guest was a guest on Desert Island Discs in 1976. He was a lifelong supporter of Chester City FC. The famous British baritone Simon Keenlyside was a chorister and subsequently a choral scholar in the choir of St John's College, Cambridge while George Guest was the choirmaster there. Actor Clive Mantle was another chorister at St. John's.
