Zoroastre (Zoroaster) is an opera by Jean-Philippe Rameau, first performed on 5 December 1749 by the Opéra in the first Salle du Palais-Royal in Paris. The libretto is by Louis de Cahusac. Zoroastre was the fourth of Rameau's tragédies en musique to be staged and the last to appear during the composer's own lifetime. Audiences gave the original version a lukewarm reception, so Rameau and his librettist thoroughly reworked the opera for a revival which took place at the Opéra on 19 January 1756. This time the work was a great success and this is the version generally heard today.
Source : Wikipedia