Born in Burgdorf, Switzerland to an Italian-Swiss father Francesco Della Casa and a Bavarian-born mother Margarete Mueller, she began studying singing at age 15 at the Zurich Conservatory, and made her operatic debut as the title role in Puccini's Madama Butterfly at Solothurn-Biel Municipal Theater in 1940. She joined the ensemble of Zurich Municipal Opera House in 1943 (staying there until 1950) and sang various parts, from the Queen of the Night in Mozart's The Magic Flute to Dorabella in Così fan tutte. Later she sang Fiordiligi. In 1949, she married Yugoslavian-born journalist and violinist Dragan Debeljevic, with whom she had a daughter, Vesna. Wikipedia Bio