Gervais was born in Bridge of Allan in Scotland. His early musical training was through private piano lessons and in the primary and secondary state schools near Glasgow. He graduated form the Royal Scottish Academy of Music and Drama (now the Royal Scottish Conservatoire) and the Jordanhill College of Education and started his teaching career. He completed a BMus at Durham University, England and a Licentiate in composition at the Royal Academy of Music in London. He emigrated to Canada and completed a BEd at Memorial University and an MEd at the University of Manitoba. He taught all grade levels including adult education and was widely in demand as a workshop presenter on various aspects of general music. He taught in Montreal, Corner Brook in Newfoundland and Winnipeg, Manitoba before accepting a position as Arts Consultant with the New Brunswick Department of Education where he had responsibilities for the development and implementation of curriculum in Music, Visual Arts, Dance and Drama.
On his retirement from public service he taught at Mount Allison University, the University of New Brunswick at Saint John and the Sandhills Community College in Pinehurst, North Carolina. In 2008 he founded Renforth Music, an independent music publishing company specializing in contemporary choral music, at first limited to composers from New Brunswick but more recently including living composers from other parts of the world.