Charlie is not to be sniffed at

Charlie is 30 and in rehab, having acquainted herself rather too well with a chemical of the same name after her life has gone terribly wrong. She's a resting actress who is now a dog-walker, she suspects her boyfriend of having an affair with her sister, and her dad walked out when she was a small child.

In anyone's else's literary universe, this would make for an hour of complex psychological probings; in Jonathan Harvey's, it's an excuse for some clever lines (sorry) and disco music.

Lord knows we don't want an hour of unremitting misery, but a bit of light and shade wouldn't go amiss in this monologue with songs performed by Abi Roberts. Harvey wrote it as a showcase for her talents and, while her singing voice is a joy, as an actor she is required to run the gamut of emotions only from A to B.

Thankfully, Harvey (who wrote the play Beautiful Thing and the TV sitcom Gimme Gimme Gimme) can do spite very well. The show's opening number is a corker: "If Helena Bonham Carter's arse/Were six foot wide and made of glass/Would it still be a thing of beauty?/I think not ..."

Roberts, a likeable and engaging performer, holds our interest well enough as she tells us how she came to be in rehab, and pulls off with aplomb the difficult task of suddenly breaking into song every 10 minutes.

Ex-EastEnder Susan Tully's direction is competent and unshowy; a touch of directorial pizzazz might have lifted the show from likeable to memorable. The ending is a sentimental cop-out, but if uncomplicated, feelgood theatre with tunes is your thing, this is one for you.

Until 30 August. Information: 0131 226 2428.