Aristotle, Poetics 4, 1449a15 = T 100 Radt
m = reading of part of the MS tradition
P = reading on a papyrus
καὶ τό τε τῶν ὑποκριτῶν πλῆθος ἐξ ἑνὸς εἰς δύο πρῶτος Αἰσχύλος ἤγαγε καὶ τὰ τοῦ χοροῦ ἠλάττωσε καὶ τὸν λόγον πρωταγωνιστεῖν πρωταγωνιστεῖν Sophianus: πρωταγωνιστὴν M παρεσκεύασεν· τρεῖς δὲ καὶ σκηνογραφίαν Σοφοκλῆς.
Aeschylus was the first to change the number of actors from one to two, and he reduced the role of the chorus and gave speech the most important role. Sophocles introduced the third actor and scene-painting.