[3][4][5] On October 16, 1935, at age 16, Dumont made her professional debut, performing on the Sweet Caporal radio show, produced by Léo Le Sieur, a pianist, organist, and composer who served as her mentor.

Radio Canada hired Dumont to participate in or host shows including Variétés françaises, Rêverie, Sur les boulevards, Le moulin qui jazze, Le p’tit bal des copains, Connaissez-vous la musique, Tambour battant and Hier, aujourd'hui.

[1] In the early stages of her career, Dumont primarily performed Lucienne Boyer's songs,[2] focusing on French music from the start.

[1] In April 1945, at a War Loan Drive concert, she performed Insensiblement, composed by Paul Misraki and conducted by Ray Ventura.

"[1] Ventura invited Dumont to travel to France and go on a performing tour; however, she turned down the offer as she would marry Jean Maurice Bailly, a sports commentator at Radio Canada, in two months.

[1] She established Atelier de la Chanson, a music school[1] in Montreal,[6] and dedicated a large amount of time to teaching,[7] explaining in an interview that she found it enriching.