Swan Lake is a ballet composed by Russian composer Pyotr Ilyich Tchaikovsky in 1875-76. Despite its initial failure, it is now considered as one of the most popular ballets of all time. The scenario, initially in two acts, was fashioned from Russian and German folk tales and tells the story of Odette, a princess who has been cursed by an evil sorcerer to live as a swan by day and a human by night and the curse can only be broken if someone who has never loved before swears to love her forever. The choreographer of the original production was Julius Reisinger (Václav Reisinger). The ballet was premiered by the Bolshoi Ballet on 4 March [O.S. 20 February] 1877 at the Bolshoi Theatre in Moscow. 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 15 January 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.