There are several stories about Mozart’s last illness and death, and it is not easy to be sure what happened. He was working on an opera "The Magic Flute" which is one of his best works and a very popular opera today. It is written in German, not Italian, like most of his other operas. In some ways it is like an English pantomime. At the same time that he was working on this he was asked by a stranger to compose a requiem. He was told to write this in secret. Then he was asked to write an Italian opera "La Clemenza di Tito", which was performed in Prague during September 1791. At the end of September "The Magic Flute" was given its first performance. Mozart then worked very hard at the "Requiem". He must have realized that he was already very ill, and that in a way the requiem (a mass for the dead) was for himself. He died in Vienna before he could finish it. Constanze asked another composer, a man called Franz Xaver Süssmayr, to finish the work. Mozart was buried in the St. Marx Cemetery.