Orfeo ed Euridice is an opera composed by Christoph Willibald Gluck, based on the myth of Orpheus and set to a libretto by Ranieri de' Calzabigi. It belongs to the genre of the azione teatrale, meaning an opera on a mythological subject with choruses and dancing. The piece was first performed at the Burgtheater in Vienna on 5 October 1762, in the presence of Empress Maria Theresa. Orfeo ed Eurid..