 At the Paris Opéra she sang Salomé in 1947 and followed this with "Thaïs", Rosenn in "Le Roi d'Ys", Portia in "Le Marchand de Venise" and "Les Indes Galantes"

Outside France Duval sang in Italy (la Scala), the Edinburgh Festival, The Colon in Buenos-Aires and Glyndebourne (Mélisande).At Monte Carlo her roles also included Fata Morgana in "The Love for Three Oranges", Musetta in "La Bohème" and "The Medium".Among her appearances in America was her 1961 "Thaïs" at the Dallas Opera, conducted by Nicola Rescigno and directed by Franco Zeffirelli.