Eli Hayes’s review published on Letterboxd :
This review may contain spoilers.
The aural narrative of Amadeus is explored via the voiceover form of narration, from the unreliable narrator Salieri, whose story shifts back and forth between past and present, both reflecting on his memories (from the future), and his present/current conflicts & actions (which could be considered the past). Mozart’s narrative in Vienna, and demise, is explored — from the future, looking back — by the elderly Salieri. Salieri’s voice is primarily utilized from a sonic perspective through his criminal-confession to a priest. Since the act of Salieri slicing his throat comes so early on in the film, the audience desires to understand why he commits this act of self-harm/attempted suicide, and what elements of the narrative led to him doing this.
Because the film fuses events of the past with (current/future) commentary from Salieri, the viewer is taken on a rollercoaster ride of constant shifts between time periods, and reminders that everything they are viewing is, rather than objective, taking place in Salieri's (unreliable) memory. Salieri’s confession to the priest is the perfect tool for Salieri to speak to the audience directly rather than peripherally, in a certain sense, and therefore despite him being an unreliable narrator (due also, in part, to his biases and psychological instability), we’re still incredibly invested in all that he has to say and recount.
One of the most brilliant aspects of Amadeus is its decision to stray from the (stage) source material and spend less time exploring Salieri’s torture of Mozart, and more time investigating his gradual psychological regression, giving us a greater understanding of Salieri’s damaged psyche and allowing for us to sympathize with the sinister character — due to director Milos Forman's successful attempts at psychological depth — despite fully recognizing his action of demolishing Mozart mentally.
When Mozart is finally on the verge of death, Salieri is not yet done feeding off of his misery, and his last act of betrayal towards Mozart is possibly the most horrifying in that Mozart, who believes he is scoring a piece for his late father, is actually/unknowingly writing the musical number which will be performed in commemoration of his own passing. Even when Mozart is too sick, too terminal, to compose this piece, Salieri takes over writing the score in a depressing act of antisocial & completely sociopathic cruelty.
And then ultimately, in the film’s finale, Salieri makes a statement directed at the hospital patients surrounding him — “mediocrities everywhere, now and to come, I absolve you all" — an assertion clearly meant to be just as much aimed at the viewer as it is at the patients surrounding him (and himself), asserting his mediocrity and Mozart’s genius but that we, the viewers, are not the all-powerful “Gods” (in Latin, Amadeus translates to “love of God” or the subject of God’s devotion) which he thinks we believe ourselves to be, and that we are in fact ordinary and unexceptional, as the rest of the human race is (including himself, despite his self-absorbed perspective) — a delusional & direct condemnation of an audience, and a Self, from a narcissistic but undeniably spiritual sociopath.