Hudson was born in Windsor, Ontario, Canada. His parents, Fred James Hudson and Olive Louella Pentland, were musicians. His mother played piano and accordion and sang. His father, a farm inspector who had fought as a fighter pilot in World War I, played drums, C melody saxophone, clarinet, flute and piano. Hudson moved with his family to London, Ontario, around 1940. Starting piano lessons at an early age, Hudson also played organ at his church and his uncle's funeral parlour, and performed country songs on the accordion Classically trained in piano, music theory, harmony and counterpoint, Hudson wrote his first song at the age of eleven and first played professionally with dance bands in 1949, at the age of twelve. He attended Broughdale Public School and Medway High School before studying music (primarily Bach's chorales and "The Well-Tempered Clavier") at the University of Western Ontario. During this period, he grew increasingly frustrated with the rigidity of the classical repertoire, leading him to drop out after a year.