<P> Messengers arrive in Vienna with news of Leopold's death, and in response a grief - stricken Mozart pens Don Giovanni . Salieri recognizes the dead commander as symbolic of Leopold and hatches a plan . Wearing Leopold's party mask, Salieri visits Mozart and commissions a Requiem Mass . Salieri plots to kill Mozart once the piece is finished, then premiere it at Mozart's funeral, claiming the work as his own . </P> <P> At a parody of one of Mozart's own operas, Emanuel Schikaneder (Simon Callow) asks Mozart to write an opera for his theater . Mozart, desperate for money, obliges, despite Constanze's insistence that he finish the Requiem Mass . The couple fight and Constanze leaves with their young son, Karl . </P> <P> Mozart collapses during a performance of his finished work, The Magic Flute . Salieri takes him home and offers his assistance on the Requiem . Salieri transcribes Mozart's verbal commands, and they work through the night . The next morning, a gravely ill Mozart apologizes to Salieri for his previous behavior . A guilty Constanze returns home and locks the unfinished Requiem away, only to find that Mozart has died from overwork . Mozart is taken out of the city and unceremoniously buried in a mass grave . </P> <P> Having finished his tale, Salieri asks how a merciful God could destroy his own beloved just to keep a mediocrity like Salieri from sharing in his glory . As he is pushed down the hall in a wheelchair, Salieri declares himself "the patron saint of mediocrities" and mockingly absolves the other patients of their own inadequacies . Mozart's high - pitched laugh is heard as the screen fades to black . </P>

How does mozart die in the movie amadeus