As Salieri envies Mozart's musical talent despite his absurd lifestyle ("I am a vulgar man, Your Majesty, but I assure you...my music is not"), he conspires to bring about his rival's ultimate downfall with a plot of murder and plagiarism (claiming Mozart's greatest work, the Requiem Mass in D Minor, as his own). However...God instead destroys his greatest instrument to torture Salieri for the rest of his days. In the end, however...Mozart gets the last laugh, literally. Just before the credits roll, the triumphant voice of Mozart laughing echoes across the ages as "the patron saint of mediocrity" smiles.
The only thing about this film that unsettled me was the fact that they didn't bury Mozart in a pauper's grave as they did historically; instead, they dumped him in a mass grave to rot. However, I guess for a man of Mozart's genius and vulgarity, it serves as a form of poetic justice for Salieri...God's instrument of musical genius is laid to rest in a grave fit for Black Plague carriers.
Despite that...Amadeus is a true work of art. Those who cannot see it need to look in the mirror, watch the film again and then, hopefully they'll be able to see it.