Aristotle Rhetoric 3.14.1

[1] The exordium is the beginning of a speech, as 20 the prologue in poetry and the prelude in flute-playing; for all these are beginnings, and as it were a paving the way for what follows. The prelude resembles the exordium of epideictic speeches; for as flute-players begin by playing whatever they can execute skilfully and attach it to the key-note, so also in epideictic speeches should be the composition of the exordium; the speaker should say at once whatever he likes, give the key-note and then attach the main subject. And all do this, an example being the exordium of the Helen of Isocrates; for the eristics and Helen have nothing in common. ¹ At the same time, even if the speaker wanders from the point, this is more appropriate than that the speech should be monotonous.