οὐδὲν οὖν ὁρῶ τὰς τοιαύτας ἡδονὰς ἴδιον ἐχούσας, ὅτι μόναι τῆς ψυχῆς εἰσιν, αἱ δ' ἄλλαι τοῦ σώματος καὶ περὶ τὸ σῶμα καταλήγουσιν· μέλος δὲ καὶ ῥυθμὸς καὶ ὄρχησις καὶ ᾠδὴ παραμειψάμεναι τὴν αἴσθησιν ἐν τῷ χαίροντι τῆς ψυχῆς ἀπερείδονται τὸ ἐπιτερπὲς καὶ γαργαλίζον. ὅθεν οὐδεμία τῶν τοιούτων ἡδονῶν ἀπόκρυφός ἐστιν οὐδὲ σκότους δεομένη καὶ τῶν τοίχων ‘περιθεόντων’, ὡς οἱ Κυρηναϊκοὶ λέγουσιν, ἀλλὰ καὶ στάδια ταύταις καὶ θέατρα ποιεῖται, καὶ τὸ μετὰ πολλῶν θεάσασθαί τι καὶ ἀκοῦσαι ἐπιτερπέστερόν ἐστι καὶ σεμνότερον, οὐκ ἀκρασίας δήπου καὶ ἡδυπαθείας ἀλλ' ἐλευθερίου διατριβῆς καὶ ἀστείας μάρτυρας ἡμῶν ὅτι πλείστους λαμβανόντων.’This is a modified version of the translation I found online here: 
Therefore I see nothing peculiar in those pleasures, that they should be thought to belong only to the soul, and all others to belong to the body, so far as to end there. But music, rhythm, dancing, song, passing through the sense, fix a pleasure and titillation  in the pleased part of the soul and therefore none of these pleasures is enjoyed in secret, nor wants darkness nor walls about it, according to the Cyrenaics' phrase; but circuses and theatres are built for them. And to frequent shows and music-meetings with company is both more delightful and more genteel; because we take a great many witnesses, not of a luxurious and intemperate, but of a pleasant and respectable manner of passing our time.The Quaestio here is 'That we ought to keep ourselves from pleasures from bad music and how this should be done'. Callistratus is trying to defend the idea that it would be wrong to think that the pleasures from theatre etc. are a cause of intemperance even if audiences occasionally get carried away. He doesn't think, with Aristoxenus, that only the pleasures of music should be called 'fine' but he also disagrees with Aristotle who thinks that the pleasures of music and dance belong only to rational human animals and not to non-rational animals. (Here Callistratus cites how some fish appear to take pleasure in rhythms and sounds.) Then he declares that the pleasures of dancing, songs, and the like generate pleasure in the soul such that they can (and indeed should) be enjoyed in public and in company. This, after all, is what theatres are built for. And there is nothing grubby or shameful in that.
The interesting bit for me is the phrase: τῶν τοίχων ‘περιθεόντων’, ὡς οἱ Κυρηναϊκοὶ λέγουσιν. It's pretty obscure. First, is this really a reference to some Cyrenaic philosophical vocabulary? The context seems appropriate and appropriately philosophical to think that it is. Second, if that's right, then what does it mean? We're used to thinking of the Cyrenaics as envisaging each person as in receipt of various pathê which are in themselves veridical and reliable insofar as they relate incorrigibly how the person is affected. And they will, as pathê of pleasure and pain, give good recommendations of what affections to pursue and which to avoid. But they won't give any reliable information about the nature of the external objects by which they are caused. In terms of walls and the like, I've seen the Cyrenaics (or perhaps their critics) use walls (city walls) as a metaphor before in their epistemology. Plutarch Adversus Colotem 1120C-D has the Cyrenaics holed up within themselves 'as if in a siege' (cf. 1120F). So I wonder: perhaps here Plutarch is using again this metaphor to contrast the Cyrenaics' position in which every perceiver is isolated and walled off from others with the public and communal enjoyment of theatrical and musical performances.
The other possibility (see note below) is that Plutarch is again referring to something mentioned also at 1089A, namely the Epicurean and Cyrenaic disagreement over whether one ought to have sex with the lights off. There we are told that the Cyrenaics were rather more restrained than their Epicurean hedonist rivals because they recommended doing it in the dark so as not to over-inflame the desires (Cf. QC 654D and Cic. Tusc. 5.112.)
 That 1909 translation doesn't refer to 'Cyrenaics', instead reading 'according to the women's phrase'. οἱ Κυρ. is Doehner's emendation (in his Quaestiones Plutarcheae 4 vols., 1840-63) for the MSS αἱ γυναῖκες. (Perhaps the textual uncertainty is the reason why this is not in SSR.) Both Hubert's 1971 Teubner and Minar, Sandbach and Helmbold's Loeb (Moralia vol. 9) retain οἱ Κυρ. I haven't managed to read Doehner, but the Teubner note ad loc. suggests the emendation was supported by reference to Non Posse 1089A.