The play, which opens with the aged Salieri, who has been a successful composer in the Hapsburg court under Emperor Joseph II, addresses the audience in a confession of his having killed the inimitable Amadeus Mozart because of his terrible envy of the young genius's talent. So, because Amadeus is a memory play and the audience is already aware that he has assassinated Mozart, the murder, then, is not the point of highest emotional intensity as it might normally be in a drama. Instead, it involves Salieri's bargain with God that he would live a virtuous life if he achieved fame.
When the young genius Mozart comes onto the scene and takes from Salieri his glory, the composer breaks his pact with God, and driven by insane jealousy of the young man who composes so delightfully without any effort, as though he were "taking dictation from God," as well as casting Katherina Cavalieri, Salieri’s star pupil in his comic opera, Salieri commits his great sin of pride. Then, the climax, the most moving moment of the play, comes as Salieri in a love for music greater than any other of his emotions, attends Mozart. As Mozart dictates, Salieri writes as quickly as he can, apparently acquainted with taking such dictation. However, as Mozart moves through his composition more swiftly as his genius simply flows, Salieri has trouble keeping up, but frantically writes. When he tells Mozart that he has taken everything down, Mozart says,
Then let me hear it. All of it.
The whole thing from the beginning now!
Impatiently, though, Mozart snatches the pages from him and in a feverish energy, he sings the melodies. "Salieri looks on in wondering astonishment." This scene is quite moving and is the climax, for even in death Mozart has defeated Salieri because the "Requiem" will only illuminate how mediocre Salieri's own work truly is. Should Salieri take credit for this magnificent composition, his fame will be false as he will know the truth himself and still be defeated by Mozart's genius, and still have broken his vow to God.