 He made his debut as Pelléas at the Grand Théâtre de Genève in 1941.After his Paris debut at the Opéra-Comique as Pelléas on 20 April 1941, Jansen also appeared as a singer in Fauré's "Masques et bergamasques" (January 1942), Valérien in "Malvina" (July 1945) and the title role in "Fragonard" (February 1946).Jansen recorded Pelléas in an Opéra-Comique cast under the conductor Roger Désormière in April and May 1941 with Irène Joachim as Mélisande.