In my previous article “Aristotle's Theory on Acting”, I showed that Aristotle's idea was a theoretical source of the European modern non-musical and prosaic theatre. But we can find another theoretical source which defends a musical and versified theatre in the thought of Middle Stoa, especially of Diogenes of Babylon (c. 240-c. 152BC), restored thanks to a new edition of Philodemus' On Music (2007).

Referring to Plato's theory of musical education, Diogenes justifies the Hellenistic form of the tragedy performance, focusing on the solo chant of “tragic singers [tragôidoi]”. This celebration of musical theatre is also based on the Stoic view of language and religion, which favours musical and versified speeches, considered as a natural manifestation of the greatness of gods and virtuous men, and as an auto-celebration of the life itself. According to Heraclides Ponticus, a pupil of Plato, Diogenes affirms that the musical acting practice can lead to all virtues. This theory considers the acting [hupokrisis] not as an act of disguising (“hypocrisy”), but as the means of constructing oneself as a virtuous man, referring to the model of “tragic singers” who construct their musical body through everyday training. This way of thinking about the musical, acting body offers a vision totally different from Aristotle's, who considered the same kind of body as the body of a slave.