Everything – and everyone – has limits. Finding these and testing them is the essence of relationships, and so of drama. Terrence McNally’s Frankie & Johnny in the Clair de Lune takes a couple who have tumbled into bed and need to find their way forward from there. On the surface they have many things in common. But scratch that surface and coition could be the end rather than the beginning.

Michael Lunney’s production for the Middle Ground spring tour keeps it all as low-key as Frankie’s studio apartment in a crowded West Side neighbourhood. Too low-key at times for audibility, not helped by the heavy cold from which Kelly McGillis (Frankie) is obviously suffering. As she spends much of the play minimally clad, one felt for her on a chilly Essex evening.

Frankie is a waitress who once might have had ambitions to become an actress. The small-town life from which she has meandered into one dead-end job and failed relationship after another has eroded all but a faint instinct of self-respect and self-preservation. Little means much when the alternative is nothing. It’s a part which could lack colour but McGillis ensures that Frankie is never monochrome, if occasionally monotone.

Johnny’s take on life – and on Frankie – is much more positive, overwhelmingly so in fact. Rolf Saxon makes him cheerful, bash in many ways but well-meaning for all that. You can believe in him as a cook, though I suspect that he’ll never make head chef anywhere up-market. And as a man who needs as well as wants love, in all its different guises.

The director’s setting is a blend of the squalidly realistic and the symbolic – a moonscape (albeit projected onto a too-wrinkled back-cloth) and the Statue of Liberty remind us of time and place. The play’s title refers to the classical music station to which Frankie has set her radio. Very quietly, its night-time repertoire takes us from Bach through Wagner and Franck to Debussy. The lovers’ relationship is shown to be as variable as the music which rustles behind it.