During a short return to America to visit her father in 1945, she auditioned at the Metropolitan Opera without success. Her first major break came with her Italian debut in Verona in 1947, as "La Gioconda". There, she met conductor Tullio Serafin who became her mentor and guided her towards the bel canto repertoire. She sang her first "Norma" in Florence in 1948, and the following year, as a last minute replacement, she appeared as Elvira in Bellini's "I puritani" in Venice, which was to be her first great success. 