Giselle is based on a legend according to which the ghosts of unmarried girls return to seek revenge on the living. The Wilis had already been described in a story in Heinrich Heine's de l'Allemagne, although Heine received no credit for Giselle. The immediate inspiration for the ballet came from Théophile Gautier, spurred by his infatuation with the dancer Carlotta Grisi. Elements from Victor Hugo were to be incorporated in a libretto that was realized by the writer Jules Henri Vernoy de Saint-Georges in three days, while Adam took a week to sketch the music and three to complete it, making some use of earlier material. The choreography was devised by the Paris Opéra ballet-master Jean Coralli, with Giselle's dances choreographed by Carlotta Grisi's teacher and lover Jules Perrot. Designs were by Pierre Ciceri, who had also designed the sets for La Sylphide. The ballet was first produced on 18th June 1841 at the Opéra, the Théâtre de l'Académie royale de musique, when Grisi danced Giselle, Lucien Petipa Albrecht and Adèle Dumilâtre the Queen of the Wilis, Myrthe. Various changes have been made in the ballet since 1841, not least in a number of versions given in Russia, with an early re-staging there by Perrot with Fanny Elssler, a rival Giselle, and Marius Petipa. The latter later made his own choreographic contribution to the ballet in later productions. The score includes interpolated scenes by Friedrich Burgmüller, who is best known for the peasant pas de deux in Act I of Giselle.