 In 1966, Armstrong won the Metropolitan Opera National Council Auditions, which led to her being engaged by the house for small roles.She made her debut at the Met on October 2, 1966, as one of the servants in "Die Frau ohne Schatten", under Karl Böhm, with Leonie Rysanek and Christa Ludwig.She continued to perform regularly at the Met through the spring of 1969, in roles like the Paggio in "Rigoletto" (opposite Cornell MacNeil), Annina in "La traviata" (with Virginia Zeani), and the Dew Fairy in "Hänsel und Gretel" (with Teresa Stratas as Gretel).