You should also take into account, when considering the structure of Oedipus, that it was a classical Greek Tragedy. Aristotle, in his work Poetics, is credited with defining this specific dramatic form. He wrote:
A tragedy is the imitation of an action that is serious and also, as having magnitude, complete in itself; in appropriate and pleasurable language;... in a dramatic rather than narrative form; with incidents arousing pity and fear, wherewith to accomplish a catharsis of these emotions.
So, by definition, the structure of a Tragedy was meant to incite an audience to "pity and fear" in order to have a cathartic moment of release instigated by the fall of the tragic hero.
The fall is key to the successful narrative structure of the play, because, by definition, it must inspire pity and fear in the audience. Oedipus is generally considered one of the most "perfect" tragic heroes. The pity is inspired by Oedipus' true and unrelenting desire to find the person responsible for the plague that is tormenting his city. As ruler, he takes this responsibility very personally, and the audience can sort of root for him and support him in this.
It is ulitmately, his ability to endure the misfortune he has caused himself that completes his fulfillment of the structural requirements of the tragic hero. The audience witnesses the final events of the play with the requisite mixture of fear and pity.
Aristotle himself gave the play his highest praise, calling it the greatest tragedy ever written.
The narrative structure of Oedipus Rex is that of a classical Greek play:
PROLOGUE (first act)
In this part the play opens with the form of a dialoge in which the protagonist expresses the statement on which the rest of the play proceeds. In Oedipus Rex, all the details necessary to Laius's murder are presented. From these details the plot will develop. The prologue then ends with a choral oded called the Parodos.
SCENE ONE (prologue)
In this act the protagonist repeats the statement from the porlogue, a statement that is developed by him in his speech. Then, with the introduction of a new character, the plot turns. In Oedipus Rex, the prophet Iresisas's arrival and his revelations about the birth and life of Oedipus fufill this purpose. Here, too, the conflict begins.
The importance of prophecies and the qualities of an ideal ruler are also introduced in this act. Then, the exposition ends with an ode call Stasimon I.
This act marks the rise in the action of the play. The longest act, this is divided into three scenes:
- the confrontation between Oedipus and Creon,
- the intervention by Jocasta and her efforts toward persuasion
- the dialogue between Jocasta and Oedipus
The climax is suspended as this act ends with a choral ode, the second Stasimon.
The climax follows the second act of high action. All the questions raised in the previous act find their solutions in this act. The mystery of Oedipus's ofe is solved and the play reaches its height and the tragedy is complete. In the fourth Stasimon, which ends the third scene, the chorus comments on the fate of Oedipus.
SCENE FOUR (exodus)
This scene presents the outcome of the tragedy. In this scene, the queen commits suicide and the desolate and devastated Oedipus blinds himself. Unlike the other acts, thes actions are not performed onstage; instead, they are narrated by a messenger.
Finally, the blinded Oedipus appears and alyrical dialogue between him and the Chorus is presented; this is a lament on the situation. After this lament, a long dialogue between Oedipus and Kreon concludes the play as Oedipus, a broken man, departs as the citizens of Thebes look to Kreon to find them an ideal king.