In a letter to Claude-Nicolas Thieriot on 23 April 1739 Voltaire claimed he was no longer interested in writing libretti: "As far as opera is concerned, after the still-birth of "Samson", there is no indication that I might wish to write another. The labour pains of the first have scarred me too deeply." However, by the end of the year he was at work on new libretto for a "tragédie en musique" in five acts, "Pandore", which fused the story of Adam and Eve and original sin with the Greek myths of Prometheus and Pandora. Voltaire sent a draught to Helvétius in January 1740. He extensively reworked the text following suggestions from friends and it was ready by the summer. Voltaire was initially reluctant to offer it to Rameau and considered Jean-Joseph de Mondonville as a potential composer instead. His hesitation may have been because - surprisingly, given the dramaturgy of "Samson" - "Pandore" contained extensive recitative. Nevertheless, Rameau accepted the libretto and was hard at work on the score by June, according to a letter from Voltaire. However, the project stalled and in February 1741 Voltaire was trying to persuade Madame Denis to take it on. The probable reason Rameau's enthusiasm waned was the lack of dramatic interest after the first act, but Voltaire blamed the interference of intermediaries. Voltaire again tried to interest Rameau in "Pandore" in 1745 but the two collaborated on the "comédie-ballet" "La princesse de Navarre" instead. This was not the end of the libretto's career. In 1752 Joseph-Nicolas-Pancrace Royer set it to music and the opera was rehearsed privately. Voltaire was furious to learn that alterations had been made to his text. Royer's version was never staged and the music is now lost. In 1765 Voltaire granted Rameau's pupil Jean-Benjamin de La Borde permission to produce his own setting. In spite of Voltaire and La Borde's efforts this "Pandore" never made the stage either. "Les beaux jours de l'Amour" was the title of a projected "opéra-ballet". The name appears - crossed out - on the manuscript scores of two one-act Rameau operas, "La naissance d'Osiris" and "Nélée et Myrthis", suggesting they were once part of a larger work.