The trilogy 'Oresteia' dates back exactly to the end of the war of Troy. 'Agamemnon', 'Choephor?' and 'Eumenides' treat the subject of the tragic fate of the house of Atreides. 'Agamemnon', the first book of the series 'Oresteia' we see Agamemnon returning in Greece after the conquest of Troy seated on a triumphal chariot. On another chariot, laden with spoils, follows Cassandra, his captive concubine, according to the laws of war in those times. Cassandra seized by prophetic rage, she breaks out into confused indistinct wailings. She sees also the murder, which is in readiness for her lord, and though shuddering at the reek of death, she rushes like a maniac into the house to meet her inevitable destruction. Behind the scenes are heard the groans of the dying Agamemnon. In the 'Choephor?', or 'Libation Bearers', the second of the three tragedies, Orestes avenges his father's murder by putting to death his mother; for his deed, painfully revolting, is enjoined upon him by Apollo. In the Eumenides', the concluding play of the series Oresteia, Orestes, comes, as a suppliant, straight from Argos, pursued by the Furies. Pallas finally acquits Orestes of the murder. The Furies promise to bless the land where Pallas rules and Pallas in return engages to allow them a sanctuary in the Attic domain, where they are to be called the Eumenides, or Benevolent Beings. The Oresteia by Xenakis was written in 1966 and completed in 1987 with the addition of the scene of Kassandra. It's not a precise transcription of the tragedy of Aeschylus at the same time nor being irrelevant to the original text. In Xenakis version the plain men relate the story of the kings. The chorus obtains here a crucial role. Its members interpret their own roles as well as those of the legendary kings and gods. They sing the lyrics of Aeschylus, which have been a great inspiration for the music.