One of the most pleasant theatre surprises of the past year was Mark Ravenhill’s Ben & Imo, a touching and illuminating two-hander about a musical genius and their young protégé. Ravenhill’s depiction of Benjamin Britten’s determination to pen a new opera in time for the Queen Elizabeth II’s coronation hung on an exploration of the tortured, mercurial auteur.

George Brant’s Marie & Rosetta, running at the Wolverhampton Grand theatre this week, may be a little kinder to its muses, but offers up some parallels nonetheless, and is equally quite the treat. Centring on the relationship between the ‘godmother of Rock ’n Roll’, Sister Rosetta Tharpe (Beverley Knight) and young tour recruit, Marie Knight (Ntombizodwa Ndlovu), in a single act, no-interval run through we find these two very different yet complementary women learn about one another and mine the kismet of their musical souls.

It’s a coronation of a homecoming for Wolverhampton born-and-bred Beverley Knight, who has carved out an (Olivier-nominated) name for herself as one of the most dependable leading ladies of musical theatre. Although Marie & Rosetta takes its time in getting to the singing, once Knight’s powerhouse vocals are unleashed, her transformation into Tharpe is not only complete, but is routinely show-stopping. Roll out the superlatives; Knight once again proves herself both a tour-de-force both technically and in terms of her soulful, searing evocation of the late, great Rosetta. And as stunning as her musicality is, equally impressive is her characterisation of Tharpe as a funny, feisty, no-nonsense, flawed grande dame.

But a two-hander would be nothing if partially amputated, and more than holding her own against Knight’s gigawatt presence is a tremendous Ntombizodwa Ndlovu as Marie Knight. In many ways, Ndlovu gets the more complete and transformative arc of the two, as the initially nervy, almost sycophantic gospel girl slowly begins to cast off her insecurities and hesitance and give herself over to the humanity and nuances of their music. Ndlovu is endearing, sweet and relatable, and packs a hefty emotional punch come the show’s coda in particular.

“Both ladies are formidable vocalists. When they come together… it is something truly electric.”

Both ladies are formidable vocalists. When they come together, in rousing renditions of ‘Strange Things Happening Every Day’, ‘Didn’t It Rain’ and ‘I Want a Tall Skinny Papa’ it is something truly electric.

As a showcase for its two exquisite performances, Marie & Rosetta is a thrill. As a piece of theatre exploring some important socio-political messages and themes, it can at times feel a little more pedestrian. Whilst Knight and Ndlovu both give beautiful, sincere performances, and Knight’s portrayal of Tharpe recalling performing at a venue when her friends and loved ones would not be even allowed in is particularly moving, Marie & Rosetta can occasionally lean a little too heavily on its exposition. And whilst it is a joy to hear these two ladies share their stories, and the growing chemistry and sass-backing between the two is great fun, there’s an awful lot of telling rather than showing.

Monique Touko’s direction, coupled with Lily Arnold’s set design, keeps things intimate and uncomplicated. The ladies’ playground is a 1940s funeral parlour, festooned with symbolism yet deftly staged to offer up some levels and podiums to highlight the musical moments. It’s all given just enough grandeur and flashes of glitz – right down to hidden neon signs and curtains peeling back to reveal the wonderful supporting band – to feel worthy of housing such storming performances. Whilst neither Knight nor Ndlovu play their respective instruments of choice, Touko and movement director Kloé Dean find an elegant and organic way of weaving this into the movement on stage.

As another delight of a two-hander, casting a light on often overlooked or even forgotten musical excellence, Marie & Rosetta proves itself a must-see. Whilst its book is a little uneven, and a touch too didactic where it could be more demonstrative, the sheer quality, power and irrepressible joy of its central performances simply cannot be denied. Searing, soulful and enlightening, Marie & Rosetta is a beautiful testimony to the legacy of two pioneering women who, like the show itself, should absolutely not be forgotten.