A Greek chorus, or simply chorus (Greek: χορός, khoros) in the context of Ancient Greek tragedy, comedy, satyr plays, and modern works inspired by them, is a homogeneous, non-individualised group of performers, who comment with a collective voice on the dramatic action. The chorus consisted of between 12 and 50 players, who variously danced, sang or spoke their lines in unison and sometimes wore masks.
Historian H. D. F. Kitto argues that the word "chorus" gives us hints about its function in the plays of ancient Greece: "The Greek verb choreuo, 'I am a member of the chorus', has the sense 'I am dancing'. The word ode means not something recited or declaimed, but 'a song'. The 'orchestra', in which a chorus had its being, is literally a 'dancing floor'." From this, it can be inferred that the chorus danced and sang poetry.
Plays of the ancient Greek theatre always included a chorus that offered a variety of background and summary information to help the audience follow the performance. They commented on themes, and, as August Wilhelm Schlegel proposed in the early 19th century to subsequent controversy, demonstrated how the audience might react to the drama. According to Schlegel, the Chorus is "the ideal spectator", and conveys to the actual spectator "a lyrical and musical expression of his own emotions, and elevates him to the region of contemplation." In many of these plays, the chorus expressed to the audience what the main characters could not say, such as their hidden fears or secrets. The chorus often provided other characters with the insight they needed.
Some historians argue that the chorus was itself considered to be an actor. Scholars have considered Sophocles to be superior to Euripides in his choral writing. Of the two, Sophocles also won more dramatic contests. His chorus passages were more relevant to the plot and more integrated in tragedies, where as the Euripidean choruses seemingly had little to do with the plot and were often bystanders. Aristotle stated in his Poetics: