Plato, Laws 655a

δειλῆς ἐν τοῖς αὐτοῖς τε καὶ ἴσοις ἆρʼ ὅμοια τά τε σχήματα καὶ τὰ φθέγματα συμβαίνει γίγνεσθαι; καὶ πῶς, ὅτε γε μηδὲ τὰ χρώματα; καλῶς γε, ὦ ἑταῖρε. ἀλλʼ ἐν γὰρ μουσικῇ καὶ σχήματα μὲν καὶ μέλη ἔνεστιν, περὶ ῥυθμὸν καὶ ἁρμονίαν οὔσης τῆς μουσικῆς, ὥστε εὔρυθμον μὲν καὶ εὐάρμοστον, εὔχρων δὲ μέλος ἢ σχῆμα οὐκ ἔστιν ἀπεικάσαντα, ὥσπερ οἱ χοροδιδάσκαλοι ἀπεικάζουσιν, ὀρθῶς φθέγγεσθαι· τὸ δὲ τοῦ δειλοῦ τε καὶ ἀνδρείου σχῆμα ἢ μέλος ἔστιν τε, καὶ

and a cowardly soul by troubles identical and equal, are the postures and utterances that result in the two cases similar? How could they be, when even their complexions differ in color? Well said, my friend. But in, fact, while postures and tunes do exist in music, which deals with rhythm and harmony, so that one can rightly speak of a tune or posture being rhythmical or harmonious, one cannot rightly apply the choir masters metaphor well-colored to tune and posture; but one can use this language about the posture and tune of the brave man and the coward,