 Armstrong has sung in several operatic world premieres, including Gottfried von Einem's "Jesu Hochzeit" (as Death), Giuseppe Sinopoli's "Lou Salomé", Luciano Berio's "Un re in ascolto", York Höller's "Maître et Marguerite" and Siegfried Matthus's "Desdemona und ihre Schwestern".Other celebrated roles include those in "The Ballad of Baby Doe", "The Crucible", "Susannah", "Salome", "Les contes d'Hoffmann" (as Giulietta, opposite Norman Treigle), "Bluebeard's Castle", "La voix humaine", "Lohengrin", "Pelléas et Mélisande", "Lulu", "Wozzeck", "Der Rosenkavalier", "Les troyens" (as Cassandre), "Die tote Stadt", "Parsifal", "Karl V.", "Erwartung", "Die Walküre" (as Sieglinde), "Katya Kabanova", "Montségur", "Die Frau ohne Schatten" (as the Fäberin), "Lady Macbeth of Mtsensk", "The Bassarids", "The Makropulos Case", "Fidelio", "Mathis der Maler" (as Ursula), "Tannhäuser" (as Venus, with René Kollo) and "Dialogues des Carmélites" (as Mother Marie of the Incarnation).In 1985, Armstrong was named a "Kammersängerin" in Stuttgart; in 1994, she received the title in Berlin.