Structure of Greek Tragedy
Here are the basic components of a Greek Tragedy:
Prologue: Sets forth the subject and provides the mythological background necessary for understanding the events of the play.
Parodos: Song sung by the chorus as it first enters. Named for the corridors at the front of the stage of a Greek theater.
Episode: A scene of dialogue in which one or more actors take part.
Stasimon: A choral ode that often reflects on the dialogue and events of the preceding episode.
Exodos: A processional song sung by the chorus at the end of the play offering words of wisdom related to the actions and outcome of the play.
Referenced from : http://www.library.cornell.edu/olinuris/ref/grtragedy.html