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,
Warsaw Chamber Opera Church. The theater building has been entered into the register of monuments of the city of Warsaw. The repertoire of the Warsaw Chamber Opera presents a large number of diverse musical styles and forms of works: from medieval mystery plays to the operas of the early and late Baroque opera, classic eighteenth-century pantomime, opera by Rossini, Donizetti, as well as works by contemporary composers. Warsaw Chamber Opera is known for its Mozart Festival, organized every year since 1991. Its repertoire includes all stage works of Wolfgang Amadeus Mozart. It also organizes a festival for Gioacchino Rossini and Claudio Monteverdi and