Parodos

A parodos (also parode and parodus; , "entrance," plural "parodoi"), in the theater of ancient Greece, is a side-entrance to the stage, or the first song that is sung by the chorus at the beginning of a Greek tragedy.
Side-entrance to the theater.
The parodos is a large passageway affording access either to the stage (for actors) or to the orchestra (for the chorus) of the ancient Greek theater. The parodoi can be distinguished from the entrances to the stage from the "skene", or stage building, as the two parodoi are located on either side of the stage, between the "skene" and the "theatron", or audience seating area. The term eisodos is also used.
Entrance song of the chorus.
A "parodos" is also the ode sung by the chorus as it enters the orchestra. Usually the first choral song of the drama, the parodos typically follows the play's prologue.