Usually, Greek plays open with a prologue, a scene that introduces the conflict of the play. Sophocles' contemporaries often included a monologue in which a character delivers the necessary background directly to the audience. The prologue is followed by the parados, or the entrance of the chorus. The parados is an example of a choral ode. These odes supply exposition, comment on action, and contribute to thematic development.
Odes also can suggest the passage of time.
For example, the final ode in Antigone gives Creon time to bury Polynices' body, and witness his son's suicide. Following the parados, scenes alternate with odes throughout the play. Action culminates in the exodos, or final scene. The chorus is not an uninvolved group in Sophocles' plays. The group often interacts with principal characters, engaging in dialogue.