The Greek chorus (choros) is believe to have grown out of the Greek dithyrambs and tragikon drama in tragic plays of the ancient Greek theatre. The chorus offers a variety of background and summary information to help the audience follow the performance. It comments on themes, and shows how an ideal audience might react to the drama. It also represents the population in any particular story. In many ancient Greek plays, the chorus expressed to the audience what the main characters could not say, such as their fears or secrets. The chorus usually communicated in song form, but sometimes spoke their lines in unison.