Plato, Laws 813a

ταῦτα ἡμῖν ἐν τοῖς πρόσθεν διείρηται πάντα, ἃ δὴ καθιερωθέντα ἔφαμεν δεῖν, ταῖς ἑορταῖς ἕκαστα ἁρμόττοντα, ἡδονὴν εὐτυχῆ ταῖς πόλεσιν παραδιδόντα ὠφελεῖν. ἀληθῆ καὶ ταῦτα διείρηκας. ἀληθέστατα τοίνυν. καὶ ταῦθʼ ἡμῖν παραλαβὼν ὁ περὶ τὴν μοῦσαν ἄρχων αἱρεθεὶς ἐπιμελείσθω μετὰ τύχης εὐμενοῦς, ἡμεῖς δὲ ὀρχήσεώς τε πέρι καὶ ὅλης τῆς περὶ τὸ σῶμα γυμναστικῆς πρὸς τοῖς ἔμπροσθεν εἰρημένοις ἀποδῶμεν·

all this we have already explained at length. We stated that in each case they should be adapted to a suitable festival and dedicated, and thus prove a benefit to the States, by furnishing them with felicitous enjoyment. This, too, you have explained truly. Yes, most truly. These matters also let the man who is appointed our Director of Music take over and supervise, with the help of kindly fortune; and let us supplement our former statements concerning dancing and bodily gymnastics in general.