If ever there was a dysfunctional family, it was the one in this opera, based on a Greek tragedy but deeply imbued with the ideas of Sigmund Freud. The mother Clytemnestra (mezzo-soprano Regina Resnik) and her lover Aegisthus (tenor Gerhard Stolze) have murdered the father, Agamemnon, on his triumphant return from the Trojan War. They have an excuse: Agamemnon gave his daughter Iphigenia for a human sacrifice. Another daughter, Elektra (soprano Birgit Nilsson), burns for revenge, but as a woman in a patriarchal society, she must use her brother Orestes (baritone Tom Krause) to execute her plan. Nilsson"s portrayal is a high point of her career, and the whole brilliant production matches her performance. This is not easy listening, but it puts us in touch with dark realities dangerous to ignore, and the music (after you get used to it, which may take a while) has great power. --Joe McLellan