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In 1986, she was Leonardo's Wife in Fortner's Bluthochzeit, in 1988 Frau Leimberger in Klebe's Der Jüngste Tag, in 1991 Beroë in Henze's Die Bassariden, and in 1993 Marcolfa in Fortner's In seinem Garten liebt Don Perlimplin Belisa. She frequently appeared there in contemporary operas. Her voice covered a wide range from contralto to mezzo-soprano. Killebrew was a member of the Deutsche Oper am Rhein from 1976 to 2006, and continued to perform there as a guest after that date. She was Carmen again at the Santa Fe Opera in 1975, and at the Met in 1979. She participated in the world premiere of Orff's De temporum fine comoedia at the 1973 Salzburg Festival. Killebrew appeared as Amneris in Verdi's Aida at the Salzburg Easter Festival from 1972. When the new opera house of Kennedy Center in Washington, D.C., was opened on September 10, 1971, she performed in the world premiere of Ginastera's Beatrix Cenci.
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In 1968, she performed the title role of Bizet's Carmen at the Bavarian State Opera in Munich. She appeared as a guest at the San Francisco Opera, with the Opera Company of Boston and at La Monnaie in Brussels. It was aired live in 1968 as a Saturday afternoon radio broadcast from the Met, in a performance conducted by Berislav Klobučar and with Leonie Rysanek as Sieglinde.
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She was engaged at the Metropolitan Opera (Met) in 1967, and made her debut as Waltraute in Wagner's Die Walküre in a new production conducted and directed by Herbert von Karajan, with Birgit Nilsson in the title role, Thomas Stewart as Wotan, Jon Vickers as Siegmund, Gundula Janowitz as Sieglinde, Karl Ridderbusch as Hunding and Christa Ludwig as Fricka. She won a competition in Belgium in 1966 and was also a winner in the Metropolitan Opera National Council Auditions that year. In 1965 Killebrew participated in the Aspen Music Festival and School, appearing in the role of the Mother in Stravinsky's Mavra. She studied voice at the Juilliard School in New York with Hans Heinz and Christopher West. She studied piano and horn at Temple University in Philadelphia, receiving a bachelor's degree in music education in 1963, and worked as a music teacher and music therapist.
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Killebrew was born in Philadelphia, Pennsylvania, on August 26, 1941.
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