What is the theme in Amadeus by Peter Shaffer?

Beauty is a major theme in the book. Salieri finds absolute beauty in music and so asks God to grant him the gut of artistic inspiration in his compositions He came to appreciate the beauty of music at a young age, noting, "when I was ten a spray of sounded notes would make me dizzy almost to falling." Unfortunately, he finds this absolute beauty only in Mozart's compositions. When Mozart plays, he confesses that he hears the "voice of God," and he responds with such delight that it makes him tremble.