[2] Rathburn attended Saint John High School,[3] and received a Licentiate of Music from McGill University in 1937.
[3] In 1945 he received a Young Artist Award for composition from the Los Angeles Philharmonic Orchestra.
His winning composition, "Symphonette," was performed by the L.A. Philharmonic under the baton of Alfred Wallenstein on 23 March 1945.
[4] From 1938–39, he studied at the Toronto Conservatory of Music with Healey Willan (composition), Reginald Godden (piano), Charles Peaker (organ), and Leo Smith (harmony).
[8] After his retirement from the NFB in 1976, Rathburn continued to compose; his work was featured at the Ottawa Chamber Music Festival.