He was born an only child in the Sydney suburb of Paddington, the son of a wharf labourer. His parents were frequently on the move, and by the age of 14 James had lived in 19 houses and attended 15 schools. An autodidact, he learned all he could about music of all genres, from medieval times to the present day. He also learnt cello, flute, piano and violin at the Sydney Conservatorium of Music. He gravitated to bohemian circles, and befriended such people as Tilly Devine, Bea Miles, and Sunday Reed. He became close friends with other members of the Heide Circle. In 1958 he was engaged by a Spanish dance theatre then touring Australia, as their international pianist. Under the name Jaime Sebastian he toured with them in Europe, the United Kingdom and elsewhere. He also assumed the conductor's podium for the company on the strength of his claim that he had conducted student orchestras at the Sydney Conservatorium. He composed two ballets for the dance troupe, one of which, La Espera, received 450 performances in Europe and Australia. After touring Australia under his assumed name, in 1962 he opted to remain in his home country, despite his misgivings about Australian society and culture. He became Assistant Musical Director and company pianist of the new Australian Ballet company. From 1964 until 1968 he was deeply involved in the World Record Club, inter alia writing over 200 record cover notes each year. In the 1950s and 1960s Murdoch was an active member of the International Society for Contemporary Music, serving as Secretary of its Melbourne, Sydney and Australian branches. In 1965 he directed the First Festival of Contemporary Music in Melbourne. He developed a painful contraction of the tendons through overuse of his hands, and turned from piano performance to concert promotion from a base in London, his company managing such people as Cathy Berberian, Harrison Birtwistle, Leo Brouwer, Paul Crossley, Peter Maxwell Davies and the Pierrot Players, Hans Werner Henze, Igor Kipnis, Roger Woodward, and the Budapest Chamber Orchestra. He was associated with the film maker Ken Russell, and he assisted in organising the music for The Devils and The Boyfriend. In 1973 he was the first musical adviser to the Australia Council. In 1975 he was appointed first National Director of the Australian Music Centre, and in 1980 was elected world president of the Music Information Centres Professional Branch. In 1981 he was sacked by the Music Board of the Australia Council, the funding body for the AMC, for what they perceived as inept financial administration, which they felt could not overcome his acknowledged superb vision and advocacy. He was then rehired as music consultant to the Australia Council, but was dismissed again when they deemed as inadequate his report into the state of music publishing in Australia. He responded by suing the board for unfair dismissal, which ended in an out-of-court settlement. From 1984 James Murdoch recorded 60 filmed interviews with leading writers, composers and artists, now held at the National Film and Sound Archive. As a passionate champion of Australian music and performers, he influenced composers like Richard Meale and Peggy Glanville-Hicks to return from self-imposed artistic exile overseas. After Glanville-Hicks died in 1990, he championed the Peggy Glanville-Hicks Composers Trust and Peggy Glanville-Hicks House, and he researched and wrote her biography, Peggy Glanville-Hicks – A Transposed Life. In 1990 he moved to the Indonesian island of Bali, where he remained extremely active in both Australian and Asian arts circles. He died there, aged 80, in 2010. He never married. His voluminous papers are lodged with the National Library of Australia.
Murdoch inherited a walking stick that had belonged to Frédéric Chopin. It had been given to Chopin by the monks at Valldemossa, the monastery he and George Sand stayed at on Majorca in 1838–39. Chopin returned it to the monks when he left. In 1934 the writer Robert Graves took up residence near there, and the monks gave the walking stick to him. Graves gave it to Peggy Glanville-Hicks when she stayed with him while they discussed his libretto for her opera Nausicaa, based on Graves's book Homer's Daughter. She gave it to the American pianist Oliver Daniels. After Daniels' death, his partner gave it to James Murdoch, who took it to Bali. Before his death he gave it to his friend Shane Simpson in Sydney.
