CHANGE OF SCENE AND CHANGE OF SCENERY: THE QUESTION OF 'SETS'
LIKE all Greek drama, the plays of Plautus and Terence were written for an open-air, curtainless theatre. So long as the stage lay permanently open to view, there was, in my opinion, no attempt to alter the visible background, though the imaginary scene might be changed at will. So in the medieval drama the stage might represent any desired place -- a freedom satirized by Sidney but still retained by Shakespeare. Change of scene in Greek drama seems to be confined to the earlier period; in the Eumenides the scene shifts from Delphi to Athens, in the Peace from Earth to Heaven, in the Frogs from Earth to Hades.
The innumerable theories as to Greek stage scenery which have been put forward may be arranged in two main groups. The common principle of the first group is that the actors' house, otherwise called the skené or permanent scene-building, was itself specially adapted to the needs of each play. The principle of the second group is that the permanent scene-building was concealed by 'sets'. In default of any real evidence in favour of either of these views, their supporters appeal to the text of the plays and to the evidence of vase-paintings and wall-paintings supposed to be in some measure inspired by theatrical performances. Unfortunately a major premiss is always lacking from such arguments; we have no proof that verbal descriptions of the imaginary surroundings were pictorially represented in the physical setting, or that ancient illustrations, even when they contain details which are agreed to be theatrical in origin, are in other respects faithful copies, or copies at all, of theatrical performances.
Aristotle (Poet. iv) tells us that σκηνογραϕíα and the third actor were introduced by Sophocles. Vitruvius, however, asserts (vii. praef. §11) that it was Agatharchus who first made a scaena, and that he did so when Aeschylus was active as a dramatist (or perhaps 'under the instruction of Aeschylus'). In the view of Pickard-Cambridge ( Theat. of Dion., page 124) Agatharchus 'painted an architectural design in perspective on the flat background'. Apparently what he did was to 'paint the front of the scene-building so as to give it a decorative, architectural effect, sufficiently dignified to serve as the permanent background for dramatic performances of all kinds. The early plays of Aeschylus ( Suppliants, Persae, Seven Against Thebes, Prometheus Bound) perhaps