Plato, Laws 665b

χορὸς εἴρηνται, τὸν δὲ τρίτον καὶ τὸν λοιπὸν χορὸν ἀνάγκη τοῦ Διονύσου λέγεσθαι. πῶς δή; λέγε· μάλα γὰρ ἄτοπος γίγνοιτʼ ἂν ὥς γε ἐξαίφνης ἀκούσαντι Διονύσου πρεσβυτῶν χορός, εἰ ἄρα οἱ ὑπὲρ τριάκοντα καὶ πεντήκοντα δὲ γεγονότες ἔτη μέχρι ἑξήκοντα αὐτῷ χορεύσουσιν. ἀληθέστατα μέντοι λέγεις. λόγου δὴ δεῖ πρὸς ταῦτα οἶμαι, ὅπῃ τοῦτο εὔλογον οὕτω γιγνόμενον ἂν γίγνοιτο. τί μήν; ἆρʼ οὖν ἡμῖν τά γε ἔμπροσθεν ὁμολογεῖται;

choir must necessarily be described, which is that of Dionysus. How so? Tell us; for at the first mention of it, a Dionysiac choir of old men sounds mighty strange,—if you mean that men over thirty, and even men over fifty and up to sixty, are really going to dance in his honor. That is, indeed, perfectly true. It needs argument, I fancy, to show how such a procedure would be reasonable. It does. Are we agreed about our previous proposals?