Opera in 4 acts by Gluck to lib. by Guillard after G. de la Touche's play based on Euripides. Prod. Paris 1778, London 1796, NY Met 1916 (in version by R. Strauss, 1889–90). Ger. version 1781. Also opera by Desmarets (1704), and Jommelli (1771), among others.