Hildegard Rütgers 1963. Between 1963 and 1965 she performed at the Salzburg Festival, the part of "Die Vertraute" (Her confidante) in a production of "Elektra" by Richard Strauss, conducted by Herbert von Karajan, alongside Astrid Varnay in the title role, and Martha Mödl, Hildegard Hillebrecht, James King and Eberhard Waechter in leading parts. The production of Mozart's "Die Zauberflöte" at the Salzburg Festival, with Rütgers as the Third Boy, was filmed and released as a made-for-television-movie in 1964. She appeared alongside Walter Kreppel as Sarastro, Roberta Peters as the Queen of the Night, Pilar Lorengar and Waldemar Kmentt as Pamina and Tamino,
Mozart and smallpox both children's illness to contend with, the Mozarts spent a total of four months away from Vienna. They eventually returned there and were received in the Imperial court on 19 January, 1768. The Empress, who had by now lost three children to smallpox, conversed with Frau Mozart about the disease. The remainder of the trip was not especially successful. Leopold apparently misinterpreted a chance remark of the Emperor as a firm invitation for Wolfgang to compose an opera; this resulted in Wolfgang writing "La finta semplice". However, the opera went unperformed in Vienna; the singers and musicians did not like