HE IS RUDE and immature Selfish and arrogant. He is to sufferable.

He is brilliant.

Wolfgang Amadcus Mozart began his musical career at age three. By five, he was famous for his performances on the harpsichord and violin. At 26 he arrived at the court of Emperor Joseph II where he would write his greatest music, and forever change the life of court composer Antonio Salieri. For the decade that Mozart lived in Vienna prior to his death at 36, the two musicians were locked in an unspoken rivalry for the favor of both the monarch and the Viennese public.

Playwright Peter Shaffer selected this twisted musical battle as the unlikely subject for his 1979 stage hit, Amadeus. The story of Salieri an artist driven mad by his own in adequacy, entranced audiences--and Shaffer himself. Three years later, Shaffer was probing the dense story once more as the screenwriter for a film adaptation of the award winning play. And that film, which opened this week, is no less indicate provacative than the play--and perhaps even the musicians who inspired it. To the richly layered stage production, Shaffer--and director Milos Forman--have added yet another coating of deceit, jealousy and adoration.

The story unravels in the confessional of the aged Salieri, an infirmed, half-mad man confined to a mental institute. In the opening scenes, Salieri, who has both attempted suicide and confessed to murdering Mozart, scorns the attentions of the young priest who is sent to absolve him. But perverse pride overcomes derision, and the musician cannot resist recounting the role he played in Mozart's demise.

"I can't think of a time when I didn't know his name," Salieri remembers. And so begins almost three hours of brilliant film making -- a sequence of vivid scenes not only linked, but actually thickened, by the voice of an old man captivated by his own life.

The story soon travels back to Salieri's childhood, when the Italian boy discovers his fascination with music. Pledging to pursue a life of virtue and piety, the boy in exchange requests that God grant him the talent to create immortal music. When a sudden turn of events finds the peasant boy installed as the king's composer, Salieri assumes that the heavenly powers have agreed to the bargain.

But this illusory compact is shattered in 1781, when Mozart arrives at the court of Emperor Joseph II. The older musician is at once disgusted by Mozart, who seems a spoiled self-important adolescent. When Mozart chase a giggly female companion into a room where Salieri is sneaking pastries, Italian composer inadvertently overhears the two exchange infantile jokes. "Say 'say I'm sick backwards," the musical prodigy insists, his words punctuated by an obnoxious high pitched giggle of his own.

However, the young composer's music transforms Salieri's disdain into awe. Even forty years later, his voice trembles as he tells the priest. "This was a music I'd never heard--it seemed to me I was hearing the voice of God." Then, outraged. "But why would God choose an obscene child to write his music?"

At first, Salieri redoubles his own musical efforts in an effort to equal the younger man's work. But Mozart's brilliance, coupled with his rudeness, proves too much for Salieri. Salieri becomes obsessed by his own inadequacy: "All I ever wanted was to sing to God. He gave me that longing, then made me mute." With his rival's music never far from his ears, Salieri's frustration soon hardens to rage. Convinced that God has chosen Mozart as his voice on earth, Salieri vows to undermine the God who betrayed him by destroying the musical prodigy.

In the carefully mannered world of the Viennese court, such treachery is not hard to achieve. By playing off the Italian and German musical factions, Salieri insures that Mozart's operas--such as Don Giovanni and The Marriage of Figaro--are yanked from the stage after only a handful of performances. Without official patronage, Mozart falls into debt and disfavor at the court.

Yet, Salieri cannot drown the haunting elegance of his rival's work. Even though the public prefers his own sing or melodies, Salieri is tormented by the knowledge that Mozart alone possesses true genius. And so the jealous man seizes upon a plan of total destruction. In a voice that carries no hint of remorse, the aged composer reveals to the speechless Priest his decision to commission a requiem from Mozart, and then murder his rival. At the funeral, the cathedral would swell with a stirring mass for the dead musician, written by his devoted friend Antonio Salieri.

The stage version of Amadeus is the vindication of Salieri's frustrated quest for immortality. If audiences did not gain any greater impression of his gain any greater impression of his musical talents, Salieri at least became unforgettable in the depth of his jealous passion. But translated to the screen, Amadeus becomes Mozart's own. Shaffer and Forman preserve the intensity of the Salieri-Mozart rivalry, but the film is permeated with the pulse and rhythm of the headstrong child who could compose "as if taking dictation."

In addition to scenes from the operas such as The Magic Flute and Abduction from the Sevaglio--reproduced in pain-staking detail in Czechoslovakia -- soundtracks of Mozart's many shorter works play throughout the film. Greater emphasis falls--upon the forces that shaped Mozart's work: the adoring but somewhat insipid "Stanzie," who can't understand why her husband has no pupils; the domineering and disapproving father Leopold, whose death would prove the terrifying inspiration for Don Giovanni, and Mozart himself, whose violent genius was not tempered by even a hint of modesty or pragmatism.

Against lush backdrops of the Viennese court, Tom Hulce creates an energetic Mozart, frivolous on all concerns save music. As Saleri, F. Murray Abraham creates an ideal counterpart: a composer as measured, reasonable, and altogether average as his rival is extraordinary. Their prickly relationship reaches a moving climax in the film's final minutes, with a scene that mesmerizingly unravels the fabric of admiration and betrayal between the two men.

AS SALIERI finishes his story, his voice carries the hushed excitement of the insane. In cracked tones, he dubs himself the "patron saint" of mediocrity--mediocre, of course, in all but the complexity of his adoration and hatred for Amadeus.