“I just want to hear how you feel,” insists Henry Goodman’s studious psychiatrist Dr Feldmann in the opening scene of Tom Kempinski’s two‑hander.

Whether or not he truly does just want to hear, a tsunami of feelings batters his ears across six sessions of therapy with Juliet Stevenson’s Stephanie, a fortysomething violinist in the grip of multiple sclerosis.

The “duet for one” of the title is Stephanie’s journey of reluctant self‑acknowledgement. She comes to terms with the implications of her condition not by slow degrees but in wild fits and starts, graduating from the elegant pleasantries of her first meeting with Feldmann, through flighty and then shrewish denial, to hostility and self-lacerating grief.

Feldmann, who barely has to turn the pages as Stephanie rockets from adagio to prestissimo, initially seems a caricature of the knowing Teutonic shrink, a fraudulent Freud-lite. But his is a carefully measured performance and its early forced restraint is brilliantly exploded in the strong second half. Matthew Lloyd’s revival of this early Eighties success has been lovingly conceived. Lez Brotherston’s design is richly imagined and the production bubbles with piquant details: the descent of Stephanie’s wardrobe from buttock-hugging Armani to frumpy cast-offs a perfectly calibrated index of her mood. No detail resonates more plangently than the word emblazoned on her motorised wheelchair: Karma.

Stevenson as the karmically challenged Stephanie is the evening’s star. Her performance is nuanced, unsentimental and affecting. As a dissection of the redemptive powers of music (and of therapy), Duet for One is not wholly credible but as a platform for a protean actor at the height of her powers it works stunningly. 

Until 1 August (0844 811 0053).