As some audience have the tendency to compare the characters, invented by the author, entirely with their real models, it is advised to be clarified, that Shaffer employed Mozart and Salieri with fictional personalities. The characters are fabricated from a blend of imaginative and factual features. Shaffer took some historically known facts with lapses from other sources, for instance Mozart’s correspondence and Pushkin’s drama Mozart and Salieri, first performed in 1832 and integrated them in the play (Shaffer “Longman” xiii). Together they make an essence of the drama with a determined purpose to emphasise the style of the characters’ behaviour, their mental processes and ambitions.
A number of narrative details have found their way into Amadeus composer, for instance, his envy of the careless ease with which Mozart can write music of unarguable genius, finally, his decision – while pretending to be the younger man’s friend – to engineer his destruction. (Shaffer “Longman” xiii)
In the play, the author intentionally exaggerates Mozart’s speech with rhyming, affectionately childish language in order to put it in a contrast with his geniality. His frequent quotes like “telling selling me that my uncle curbuncle” or “today the letter setter from my Papa Ha! Ha!” (Shaffer “Longman” xv) only underline the Mozart’s resistance to accept the moral concept of those days. As mentioned in the Introductionto the play Amadeus, Peter Shaffer was inspired, among other things, by Mozart's correspondence with his cousin Anna Marie Thekla, in which he occasionally employs rhymed, playful style of a language with a number of faecal vocabulary and sexual allusions (Longman xv). By applying this characteristic and unique expressional device in the play, Shaffer seasoned Mozart's behaviour and manners of speech with the pure intention to withdraw an acquired urge of idealizing geniuses as people with exquisite taste and behaviour.
Therefore, both the reader and the spectator should be aware of the fact that the fictional arrangements help to run the story in a more dramatic way and, secondly, highlight the irony of life and mental changes that both protagonists experience. Some audience, nevertheless, responded negatively to such a radical intervention to their concept of Mozart, since they did not want to accept a Mozart as a fictional dramatic character that giggles dottily towards them from the stage (Shaffer, Hilský 35).