Plato, Laws 665c

τοῦ πέρι; τὸ δεῖν πάντʼ ἄνδρα καὶ παῖδα, ἐλεύθερον καὶ δοῦλον, θῆλύν τε καὶ ἄρρενα, καὶ ὅλῃ τῇ πόλει ὅλην τὴν πόλιν αὐτὴν αὑτῇ ἐπᾴδουσαν μὴ παύεσθαί ποτε ταῦτα ἃ διεληλύθαμεν, ἁμῶς γέ πως ἀεὶ μεταβαλλόμενα καὶ πάντως παρεχόμενα ποικιλίαν, ὥστε ἀπληστίαν εἶναί τινα τῶν ὕμνων τοῖς ᾄδουσιν καὶ ἡδονήν. πῶς δʼ οὐχ ὁμολογοῖτʼ ἂν δεῖν ταῦτα οὕτω πράττεσθαι;

In what respect? That it is the duty of every man and child—bond and free, male and female,—and the duty of the whole State, to charm themselves unceasingly with the chants we have described, constantly changing them and securing variety in every way possible, so as to inspire the singers with an insatiable appetite for the hymns and with pleasure therein. Assuredly we would agree as to the duty of doing this.