It’s just 90 minutes long, somewhat slight and meandering, yet this quirky little show manages to make a surprisingly big splash. A 2003 musical by the Tony-nominated American Michael John LaChiusa, it’s inspired by the short stories of Deborah Eisenberg. The influence of Sondheim — and in particular of Company, his study of metropolitan singleton life — hovers in the episodic plot in a score that sets the fidgety and dissonant alongside the soaringly melodic and in lyrics that are sometimes tender, often acerbic. There’s a hint of Gershwin to the music too, with Rhapsody in Blue tingeing the tunes just enough to trace an aural image of the Manhattan skyline.

The downside is that this tale of one woman’s journey of self-discovery can be mawkish, and its sexual politics are crude. But there’s enough verve and bitter wit, both in LaChiusa’s writing and in Adam Lenson’s persuasive production, to keep it sharp rather than saccharine.

Charlotte, a New Yorker, has given up cigarettes and finds that, once the fug of tobacco smoke clears, she can suddenly see herself with frightening and unflattering clarity. Her friends suggest various distractions — doll-collecting, a new drug habit — from which she chooses the least ludicrous: swimming. Ploughing up and down the pool at the YMCA, she is haunted by her past mistakes and missed opportunities. Gradually she realises that she has barely dipped a toe into the dangerous current of life — and that to survive, she needs to stop swimming alone.

The aquatic motif is overworked and sentimental, but Charlotte’s quest to overcome the damage done to her by an abusive relationship and to reconnect emotionally in a high-speed, atomised society engages, even if it rarely surprises. Like Charlotte’s frustrated friends, you often want to shake her — but in a fine central performance from Julia Worsley, her flaws add interest and appeal to a character who isn’t immediately likeable.

And Worsley is supported by a cast of excellent actor-singers who, aided by Nick Cunningham’s nimble choreography and Bec Chippendale’s ingeniously economical blue set, create a whole world of urban angst on the Finborough’s tiny stage. Its waters may not run all that deep; but they’re still well worth wading into.

Box office: 0844 8471652, to Nov 21

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