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,
Wolfgang Amadeus Mozart and Prague pointed out how precarious opera production was in the city throughout the eighteenth century. Indeed, productions of Italian opera in Prague ceased again already in 1789, not to re-appear again until 1791, due to the departure of the impresario Domenico Guardasoni and the death of the impresario Pasquale Bondini. Another possible reason why Mozart didn't stay is given by Volkmar Braunbehrens, citing Schenk: the death in Vienna in November 1787 of Gluck, whose post in the Imperial musical establishment Mozart sought (and ultimately got, though at a much lower salary); Mozart needed to return home to lobby for the position.