There are two tasks here for a reviewer, to say something rudely meaningful about the Oresteia, one of the seminal works of world literature, and to pass some sort of judgment on the current translation, in this case by the great American poet Robert Lowell. The star-rating system is of no utility in such a situation; five hundred stars wouldn't suffice for the original text, though three or four would be ample for the English version per se.
The Oresteia, by the Athenian Aeschylus(525-456 BCE), is the only surviving complete trilogy of Greek drama; the three plays, originally performed in a single day, are "Agamemnon", "Orestes" (The Libation Bearers), and "The Furies". The first two dramatize: 1. the murder of Agamemnon, by his wife Clytemnestra and her lover Aegisthus, upon the Argive king's return from the Trojan War, 2. the slaying of Aegisthus and Clytemnestra by her son Orestes, as commanded by the god Apollo and assisted by his sister Electra. These plots are based on Homeric legends already of venerable antiquity in the lifetime of Aeschylus, and they have received the most theatrical attention in recent centuries, as representing perplexing moral dilemmas. The third play of the trilogy, however, is quite antithetical to Homeric tradition; in it, Orestes is guided to Athens by the 'younger' gods Apollo and Mercury, to escape the inexorable curse of revenge represented by The Furies, the pre-Olympian immortals who pursue Orestes as a matricide. Athenian justice, personified by the goddess Athena, intervenes; Athena conducts a trial, with a jury of twelve mortal Athenians, which acquits Orestes on the grounds of 'equity' rather than strict observance of legalities, and despite the threats of the Furies against the welfare of the city. In the end, Athena persuades the Furies to 'settle' in Athens as spirits of a newer justice. The whole trilogy, therefore, is above all a foundational paean to the Athenian democracy, comparable in ways to Shakespeare's Henry VIII as an acclamation of cultural pride. It's the third play of the trilogy that swept Athenians audiences with rapture at the playwright's genius. I dug out my two copies of the Oresteia, this one by Lowell and another by E.D.A. Morshead from 1909, in response to my recent reading of I.F. Stone's "The Trial of Socrates".
Robert Lowell's 'Oresteia' is not a translation so much as an abridged adaptation, intended to be staged as a three-act play of ordinary length for a modern audience. I've never seen such a staging, and I'm skeptical that it would be successful. But honestly, I've never seen a 'faithful' staging of any Greek drama that I thought truly successful. Adaptation is surely "the way to go" for the modern theater, but Lowell didn't "go" far enough. His version has the advantage of being fairly crisp and readable as dramatic prose, but it's too selective and skimpy as full translation. That is to say, it's neither "fish nor fowl" - neither a stageable play nor an ample translation. I was in fact a student of Robert Lowell's at Harvard when he began the project, and I know from conversation that he had two goals in mind; 1. the fostering of a new model of translation, as exemplified in his book "Imitations", and 2. the fulfillment of the Renaissance humanists' efforts to re-invent 'civic' drama of the highest cathartic seriousness, such as they supposed the Athenians had supported. Lowell effectively abandoned the Oresteia project after completing the first two plays; he returned to it after the Vietnam struggles, in 1977, just a year before his death. He never saw it produced in its entirety.
The Morshead translation, first published as vol. 8 of The Harvard Classics, is unreadable, full of pompous syntax and jangling rhymes, replete with archaic language that alludes more to Medievalism than to classic Greece. It has been re-issued as a Dover Thrift Edition but, to be blunt, it should be retired forevermore. Any poor reader who encounters Aeschylus in this form first will never be tempted to look at another Greek drama.