The House of Atreus Act I, released in 1999 is the first part of a metal opera inspired by the  only extant example of an ancient Greek theatre trilogy which won first prize at what festival?
Oresteia The Oresteia (Ancient Greek: Ὀρέστεια ) is a trilogy of Greek tragedies written by Aeschylus concerning the murder of Agamemnon by Clytaemnestra, the murder of Clytaemnestra by Orestes, the trial of Orestes, the end of the curse on the House of Atreus and pacification of the Erinyes. The trilogy—consisting of "Agamemnon" (Ἀγαμέμνων ), "The Libation Bearers" (Χοηφóρoι ), and "The Eumenides" (Εὐμενίδες )—also shows how the Greek gods interacted with the characters and influenced their decisions pertaining to events and disputes. The only extant example of an ancient Greek theatre trilogy, the "Oresteia" won first prize at the Dionysia festival in 458 BC. Many consider the "Oresteia" to be Aeschylus' finest work. The principal themes of the trilogy include the contrast between revenge and justice, as well as the transition from personal vendetta to organized litigation. "Orestia" originally included a satyr play, "Proteus" (Πρωτεύς ), following the tragic trilogy, but all except a single line of "Proteus" has been lost.
Phrynichus (comic poet) Phrynichus ( ; Greek: Φρύνιχος ) was a poet of the Old Attic comedy and a contemporary of Aristophanes. His first comedy was exhibited in 429 BC. He composed ten plays, of which the "Solitary" ("Μονότροπος ") was exhibited at the City Dionysia in 414 along with the "Birds" of Aristophanes and gained the third prize. The "Muses" carried off the second prize at the Lenaia in 405, Aristophanes being first with the "Frogs", in which he accuses Phrynichus of employing vulgar tricks to raise a laugh, of plagiarism and bad versification, and of lowbrow politics.