The chorus inform the audience of the happenings of the play at the very beginning.
Two instances of uncontrollable fate in the play: Romeo and Juliet meets despite being committed to Rosalind and Paris respectively.
Romeo's impulsivity leads to his death and thus Juliet's.
Oedipus gains status and power after being adopted by the King and Queen of Corinth, Polybus and Merope
Oedipus murders his real father, Laius, and sleeps with his true mother, Jocasta, just as prophesied.
The chorus mocks Oedipus blindness, stating it was with him since birth, after he ignores a prophecy. It's ironic as he gauged his eyes out when he learned the truth.