Anton Haizinger heard Haizinger sing in concerts, and offered him an engagement at the theatre; Haizinger gave up teaching. Haizinger's first roles at Theater an der Wien, in 1821, were in two operas by Rossini, as Gianetto in "La gazza ladra" and Lindoro in "L'italiana in Algeri". He soon became well-known in Vienna. The role of Adolar in Weber's opera "Euryanthe", premiered in 1823 at the Theater am Kärntnertor, was created for him, and he was a soloist in the premiere in 1824 of Beethoven's Ninth Symphony at the same theatre. He continued studies with Antonio Salieri. At this time, Italian opera
La Fenice sooner had the opera house been rebuilt than a legal dispute broke out between the company managing it and the owners, the Venier family. The issue was decided in favor of the Veniers. At the beginning of the 19th century, La Fenice acquired a European reputation. Rossini mounted two major productions there: "Tancredi" in 1813 and "Semiramide" in 1823. Two of Bellini's operas were given their premieres there: "I Capuleti e i Montecchi" in March 1830 and "Beatrice di Tenda" in March 1833. Donizetti, fresh from his triumphs at La Scala in Milan and at the Teatro di San Carlo