After characterizing the classic Greek tragedy as an expression of a citizen art, which participates equally from one festive character, a certain discursive regime and a clear physical and spatial inscription, the text is delayed on considering three fundamental aspects of this dramatic form invented by the Greeks; a knowledge: an exhibition about mythical oral sources in which the authors are part of composing the history of each of the pieces that are taken into the scene under an agonal spirit; an explanation of the formal functioning of the tragedy, based on the alternation of the sung parts (chorus) and the recited parts (hero); and finally, a stage direction of the sense - internal and external-which the dramatic action possess, as an articulation element of the plot.