structural:scholar_edition, information:extraction, structural:summarization
Final illness and death

Mozart fell ill while in Prague for the premiere, on 6 September 1791, of his opera La clemenza di Tito, which was written in that same year on commission for Emperor Leopold II 's coronation festivities. He continued his professional functions for some time and conducted the premiere of The Magic Flute on 30 September. His health deteriorated on 20 November, at which point he became bedridden, suffering from swelling, pain, and vomiting.

Mozart was nursed in his final days by his wife and her youngest sister, and was attended by the family doctor, Thomas Franz Closset. He was mentally occupied with the task of finishing his Requiem, but the evidence that he dictated passages to his student Franz Xaver Süssmayr is minimal.

Mozart died in his home on 5 December 1791 (aged 35) at 12:55 am. The New Grove describes his funeral:

Mozart was interred in a common grave, in accordance with contemporary Viennese custom, at the St. Marx Cemetery outside the city on 7 December. If, as later reports say, no mourners attended, that too is consistent with Viennese burial customs at the time; later Otto Jahn (1856) wrote that Salieri, Süssmayr, van Swieten and two other musicians were present. The tale of a storm and snow is false; the day was calm and mild.

The expression "common grave" refers to neither a communal grave nor a pauper's grave, but an individual grave for a member of the common people (i.e., not the aristocracy). Common graves were subject to excavation after ten years; the graves of aristocrats were not.

The cause of Mozart's death is not known with certainty. The official record of hitziges Frieselfieber ("severe miliary fever", referring to a rash that looks like millet seeds) is more a symptomatic description than a diagnosis. Researchers have suggested more than a hundred causes of death, including acute rheumatic fever, streptococcal infection, trichinosis, influenza, mercury poisoning, and a rare kidney ailment.

Mozart's modest funeral did not reflect his standing with the public as a composer; memorial services and concerts in Vienna and Prague were well attended. Indeed, in the period immediately after his death, his reputation rose substantially. Solomon describes an "unprecedented wave of enthusiasm" for his work; biographies were written first by Schlichtegroll, Niemetschek, and Nissen, and publishers vied to produce complete editions of his works.