Plato, Laws 656d

νῦν δέ γε αὐτὸ ὡς ἔπος εἰπεῖν ἐν πάσαις ταῖς πόλεσιν ἔξεστι δρᾶν, πλὴν κατʼ Αἴγυπτον. ἐν Αἰγύπτῳ δὲ δὴ πῶς τὸ τοιοῦτον φῂς νενομοθετῆσθαι; θαῦμα καὶ ἀκοῦσαι. πάλαι γὰρ δή ποτε, ὡς ἔοικεν, ἐγνώσθη παρʼ αὐτοῖς οὗτος ὁ λόγος ὃν τὰ νῦν λέγομεν ἡμεῖς, ὅτι καλὰ μὲν σχήματα, καλὰ δὲ μέλη δεῖ μεταχειρίζεσθαι ταῖς συνηθείαις τοὺς ἐν ταῖς πόλεσιν νέους· ταξάμενοι δὲ ταῦτα, ἅττα ἐστὶ καὶ ὁποῖʼ ἄττα ἀπέφηναν ἐν τοῖς ἱεροῖς,

But at present this licence is allowed in practically every State, with the exception of Egypt. How, then, does the law stand in Egypt? It is marvellous, even in the telling. It appears that long ago they determined on the rule of which we are now speaking, that the youth of a State should practise in their rehearsals postures and tunes that are good: these they prescribed in detail and posted up in the temples,