Plato, Laws 656a

τοὺς ἐπαίνους ἐναντίους προσαγορεύουσιν· ἡδέα γὰρ τούτων ἕκαστα εἶναί φασι, πονηρὰ δέ, καὶ ἐναντίον ἄλλων οὓς οἴονται φρονεῖν αἰσχύνονται μὲν κινεῖσθαι τῷ σώματι τὰ τοιαῦτα, αἰσχύνονται δὲ ᾄδειν ὡς ἀποφαινόμενοι καλὰ μετὰ σπουδῆς, χαίρουσιν δὲ παρʼ αὑτοῖς. ὀρθότατα λέγεις. μῶν οὖν τι βλάβην ἔσθʼ ἥντινα φέρει τῷ χαίροντι πονηρίας ἢ σχήμασιν ἢ μέλεσιν, ἤ τινʼ ὠφελίαν αὖ τοῖς πρὸς τἀναντία τὰς ἡδονὰς ἀποδεχομένοις; εἰκός γε.

for whereas they say of a performance that it is pleasant but bad, and feel ashamed to indulge in such bodily motions before men whose wisdom they respect, or to sing such songs (as though they seriously approved of them), they really take a delight in them in private. Very true. Does the man who delights in bad postures and tunes suffer any damage thereby, or do those who take pleasure in the opposite gain therefrom any benefit? Probably.