Swan Lake (Russian: Лебединое озеро, Lebedinoye ozero) ballet, op. 20, by Pyotr Tchaikovsky, was composed 1875–1876. The scenario, initially in four acts, was fashioned from Russian folk tales and tells the story of Odette, a princess turned into a swan by an evil sorcerer's curse. The choreographer of the original production was Julius Reisinger. The ballet was premièred by the Bolshoi Ballet on March 4 [O.S. February 20] 1877 at the Bolshoi Theatre in Moscow, billed as The Lake of the Swans. Although it is presented in many different versions, most ballet companies base their stagings both choreographically and musically on the 1895 revival of Marius Petipa and Lev Ivanov, first staged for the Imperial Ballet on January 15, 1895, at the Mariinsky Theatre in St. Petersburg. For this revival, Tchaikovsky's score was revised by the St. Petersburg Imperial Theatre's chief conductor and composer Riccardo Drigo.
Many critics have disputed the original source of the Swan Lake story. The Russian ballet patriarch Fyodor Lopukhov has called Swan Lake a "national ballet" because of its swans, who originate from Russian lyrically romantic sources, while many of the movements of the corps de ballet originated from Slavonic ring-dances. According to Lopukhov, "both the plot of Swan Lake, the image of the Swan and the very idea of a faithful love are essentially Russian". The libretto is based on a story by the German author Johann Karl August Musäus, "Der geraubte Schleier" (The Stolen Veil), though this story provides only the general outline of the plot of Swan Lake. The Russian folktale "The White Duck" also bears some resemblance to the story of the ballet, and may have been another possible source. The contemporaries of Tchaikovsky recalled the composer taking great interest in the life story of Bavarian King Ludwig II, whose tragic life had allegedly been marked by the sign of Swan and who—either consciously or not—was chosen as the prototype of the dreamer Prince Siegfried