The chorus in Oedipus, the King is an additional set of characters, the Theban elders. They are divided into “strophe” and “antistrophe” for the difference. They represent “the people” of the city, and they alternately pray, bemoan their fate, or criticize the King. They were probably placed in different locations so that they would seem like a discussion among the muses or maybe even nymphs. The voice the questions of the audience. They also served to give the cast time for a brief rest, rather like an amusing but short intermission.
At the end of the first scene, the two groups of three sets of voices: strophe and antistrophe 1,2, and 3, pray to Athena, pray that war (Ares) will not come, and they openly mourn the dead and fear the future. By these means, they explain the situation, filling in where prose would have blocks of exposition, the chorus is providing this in conversation and prayer.
The chorus also provides responses and advice to the King, symbolizing his subjects as here just following the first scene:
Aye, if there be a third best, tell it too.
Oedipus
My liege, if any man sees eye to eye
With our lord Phoebus, ’tis our prophet, lord
Teiresias; he of all men best might guide
A searcher of this matter to the light.
Chorus
They act as his conscience and his guide, and even his alter-ego or “devil’s advocate” as the Kind puzzles out the problems and mysteries. After all, the elders are supposed to be wise. A long scene follows between the King and Tereslas, and the chorus interrupts with a polite criticism:
To us, it seems that both the seer and thou,
O Oedipus, have spoken angry words.
This is no time to wrangle but consult
How best we may fulfill the oracle.
Chorus
TEIRESIAS and OEDIPUS talk some more and then exit, and the chorus once more takes over. They argue over the guilt or innocence of both Oedipus and Creon. They also supply a foreshadowing of things to come:
Sore perplexed am I by the words of the master seer.
Are they true, are they false? I know not and bridle my tongue for fear,
Fluttered with vague surmise, nor present nor future is clear.
The quarrel of ancient date or in days still near know I none
For the next scene, the chorus switches to respond to Creon and be his alter-ego, his “people” as he protests his innocence. Oedipus enters and the chorus stays silent until the main part of the discussion between Oedipus and Creon is done. The chorus makes only a couple more comments until Jocasta enters. She speaks on behalf of Creon and the chorus supports her.
Believe him, I adjure thee, Oedipus,
First for his solemn oath’s sake, then for mine,
And for thine elders’ sake who wait on thee.
Jocasta
Hearken, King, reflect, we pray thee, but not stubborn but relent.
Chorus
Creon leaves and Jocasta now carries on a discussion with the chorus. After this long scene with little said by the chorus, it takes up the task of summarizing what has passed and of voicing the fear that the oracle is not to be trusted. The chorus becomes background once again until it is time to voice the deepest fears of the King, that he is his wife’s son. And has killed his father.
Strophe
If my soul prophetic err not, if my wisdom aught avail,
Thee, Cithaeron, I shall hail,
As the nurse and foster-mother of our Oedipus shall greet
Ere tomorrow’s full moon rises, and exalt thee as is meet.
Dance and song shall hymn thy praises, lover of our royal race.
Phoebus, may my words find grace!
Chorus
Antistrophe
Child, who bare thee, nymph or goddess? sure thy sure was more than man,
Haply the hill-roamer Pan.
Of did Loxias beget thee, for he haunts the upland world;
Or Cyllene’s lord, or Bacchus, dweller on the hilltops cold?
Did some Heliconian Oread give him thee, a newborn joy?
Nymphs with whom he loves to toy?
Chorus
After this, the messenger arrives and the truth is revealed. After Oedipus is led away, the chorus ends the play with a lament for him: the greatest of men, who fell so low. The great mystery of who he killed on the road, and how he came to be king is resolved. While we sympathize, as does the chorus, we understand that it was his arrogance that causes Oedipus to kill instead of simply ignoring the insult. It is the chorus that actually states his biggest mistake, that of not understanding the oracle and not believing in its power.
References
Sophocles, 2008, Oedipus the King, The Internet Classics Archive, Web.