Chor der Priester: O Isis, und Osiris, welche Wonne!

Mozart had a particular interest in composing operas. In the 18th century, opera comprised several different traditions, of which only Italian *opera seria* and *opera buffa* had widespread international reach. Mozart was commissioned twice to compose an *opera seria* for Milan, which at the time was still a Habsburg territory on the Italian Peninsula (Mitridate, re di Ponto, K. 87 and Lucio Silla, K. 135); Idomeneo, re di Creta, K. 366 and La clemenza di Tito, K. 621 are later examples of this genre, which was ultimately abandoned around 1800. Three other works (K. 111, K. 126, and K. 208) were festive pieces, so-called serenatas, composed for a single performance on a special occasion.

After 1780, German opera gradually established itself in the German-speaking world. In 1781/82, Die Entführung aus dem Serail, K. 384 was created as part of a short-lived initiative by Emperor Joseph II to promote the German *Singspiel* (with spoken dialogue instead of *secco* recitatives) through what was known as the National Singspiel. Three *opere buffe* based on librettos by the Viennese court poet Lorenzo da Ponte – Le nozze di Figaro, K. 492, Don Giovanni, K. 527, and Così fan tutte, K. 588 – earned Mozart international acclaim. The Magic Flute, K. 620 was written for a successful suburban theater in Vienna, where Emanuel Schikaneder included more serious pieces alongside the usual comic repertoire.