Plato, Laws 799a

ἔχει τις οὖν ἡμῶν ἐπὶ τὰ τοιαῦτα βελτίω τινα τέχνην τῆς τῶν Αἰγυπτίων; ποίας δὴ λέγεις; τοῦ καθιερῶσαι πᾶσαν μὲν ὄρχησιν, πάντα δὲ μέλη, τάξαντας πρῶτον μὲν τὰς ἑορτάς, συλλογισαμένους εἰς τὸν ἐνιαυτὸν ἅστινας ἐν οἷς χρόνοις καὶ οἷστισιν ἑκάστοις τῶν θεῶν καὶ παισὶ τούτων καὶ δαίμοσι γίγνεσθαι χρεών, μετὰ δὲ τοῦτο, ἐπὶ τοῖς τῶν θεῶν θύμασιν ἑκάστοις ἣν ᾠδὴν δεῖ ἐφυμνεῖσθαι, καὶ χορείαις ποίαισιν γεραίρειν τὴν τότε

To attain this end, can any one of us suggest a better device than that of the Egyptians? What device is that? The device of consecrating all dancing and all music. First, they should ordain the sacred feasts, by drawing up an annual list of what feasts are to be held, and on what dates, and in honor of what special gods and children of gods and daemons; and they should ordain next what hymn is to be sung at each of the religious sacrifices, and with what dances