Which opera seria was composed by Mozart?

The opera seria composed by Mozart is Idomeneo, which premiered in 1781. This opera is significant because it represents Mozart's first mature opera, showcasing his mastery of combining dramatic narrative with sophisticated musical forms typical of the opera seria genre.

Idomeneo is characterized by its serious subject matter rooted in Greek mythology and features an elaborate structure of recitatives and arias that highlight the emotional depth of the characters. The music is intricate, with ensembles that demonstrate Mozart's early ability to weave together different musical lines, creating a rich tapestry of sound.

In contrast, The Magic Flute is classified as a singspiel, which combines spoken dialogue with songs and is more comedic in nature. Don Giovanni is a dramma giocoso, blending elements of both opera seria and comic opera, making it distinct from the traditional opera seria form. Cosi fan tutte, although composed by Mozart, is also a comic opera rather than an opera seria.

Idomeneo's adherence to the conventions of opera seria, along with its depth and complexity, marks it as a pivotal work in Mozart's oeuvre and aligns with the characteristics associated with that specific genre.