After failing to establish himself as an actor in the 1950s, Dor undertook a career in radio as a disk jockey and news director. In 1964 he was encouraged by friends to compete in an amateur singing competition. He began singing professionally in early 1965, and released his first album in 1966. One of the songs from this album, his composition "La Complainte de La Manic," whose lyric was a love letter written by a construction worker on the Manicouagan power project, became the most successful record ever by a Quebec chansonnier.
He continued to perform as a singer till 1972, and to record till 1978. After that he worked mainly in the theatre and in television, producing and writing plays and téléromans. He also wrote two novels and published several collections of poetry, among other artistic and critical accomplishments.