In "Oedipus Rex," the chorus shows the horrors of the plague and fear about the coming message from the Oracle at the play's start and later moves on to comment about the nature of humanity. In general, the role of the chorus in Greek tragedy was to signal the beginning and ending of the story with song and to provide commentary about the events and actions in the play.
As "Oedipus Rex" progresses, the chorus proceeded to deliver a number of odes that provide comment on the scenes before it. The chorus forges peace between Oedipus and Creon, winning a pardon for Creon. After Tiresias leaves, the chorus gives its opinions about the old prophet's predictions, ultimately coming around to support Oedipus. Its most poignant moment comes after Jocasta and Oedipus give their own disrespectful opinion about the Oracle, holding fast to the Greek belief in the inevitability of destiny. In the last ode, the chorus mirrors Oedipus' general dejection, indicating that all of the actions of man basically add up to nothing. While the play itself also expresses the wonder of the human spirit, at this point in the story, matters appear gloomy. Oedipus' heroism remains true even as he trudges, blinded, out of his kingdom, leaving chaos in his wake.