The music for The Sleeping Beauty is by one of the most famous of all Russian composers, Piotr Ilych Tchaikovsky. Although he wrote music for only three ballets, Swan Lake, The Sleeping Beauty and The Nutcracker, most of his other music has been used as scores for ballets because they are so "danceable".
Tchaikovsky and Petipa worked together on the score. Petipa told Tchaikovsky exactly how many measures he wanted for each episode, and specified the tempo, the style, even the scoring. For example, “Princess Aurora’s first variation should be accompanied by violins and cellos pizzicato, and harps; at Carabosse’s unmasking, at the end of Act I, a chromatic scale must sound in the whole orchestra; the Sapphire of Act III, being of pentahedral cut, requires an accompaniment in 5/4 time.” When, during rehearsals, the Panorama music of Act II came to an end before the great panorama of painted canvas had rolled its full course, Tchaikovsky composed extra music, whose length was determined by the yard!
Perhaps the best known of all Russian composers, Tchaikovsky had a genius for creating melodies and a mastery of musical structure that allowed him to reach directly to the hearts of his listeners. Tchaikovsky revitalised ballet music, giving it stature and dignity. Except for the works of Minkus and Delibes, most ballet music was a series of mediocre tunes strung together in the flimsiest manner. With Swan Lake, The Sleeping Beauty and The Nutcracker, ballet music was raised to its highest level.