breakthrough the following year when she appeared as the Queen of the Night in Mozart's Die Zauberflöte. In 1971, Gruberová decided to emigrate to the West. She became a member of the Vienna State Opera in 1972, where she was only given secondary and supporting roles in her early years. She was invited to perform at many of the most important opera houses in the world, especially in coloratura roles. Gruberová made her debut at Glyndebourne in 1973 as the Queen of the Night. She became an Austrian citizen in 1974. In Vienna, she studied with Ruthilde Boesch, whom she described as a wonderful, tough, diligent teacher, the demanding role of Zerbinetta in Ariadne auf Naxos by Richard Strauss. Although a guest was planned to sing the role in a new production in 1976, Gruberová convinced conductor Karl Böhm that she was capable. The premiere won her international recognition, and Böhm said he wished that the composer could have heard that performance. Gruberová first appeared at the Metropolitan Opera, New York City in 1977, again as the Queen of the Night, conducted by James Conlon. She appeared as Zerbinetta in a live broadcast conducted by James Levine in 1979. Robert Jacobson of Opera News, in his review noted: In 1977, she first appeared at the Salzburg Festival, as Thibault in Verdi's Don Carlo, conducted by Herbert von Karajan. In opera films, she performed as Gilda in Ponnelle's 1982 film adaptation of Rigoletto, alongside Ingvar Wixell in the title role and Luciano Pavarotti as the Duke, and in his 1988 film adaptation of Mozart's Così fan tutte, alongside Delores Ziegler and Ferruccio Furlanetto. Gruberová made her Royal Opera House debut as Giulietta in Bellini's I Capuleti e i Montecchi in 1984. Other important roles include the title roles of Verdi's La traviata, Donizetti's Lucia di Lammermoor, and Massenet's Manon. She performed as Konstanze in Mozart's Die Entführung aus dem Serail, and Oscar in Verdi's Un ballo in maschera. Gruberová appeared as a regular guest at the Zürich Opera, as Marie in Donizetti's La fille du régiment in 1984, as Lucia in 1990, and in the title role of Rossini's Semiramide in 1992. She performed there in the title role of Donizetti's Linda di Chamounix in 1995, as Elvira in Bellini's I puritani in 1999, in the title role of Donizetti's Anna Bolena in 2000, and in the title role of Bellini's