The National Theatre of Scotland has done more to demean Scotland’s cultural reputation than anything I can think of

West End producers are itching to get their hands on the new show at the Bush. Mama Mia’s director, Phyllida Lloyd, takes charge of a script written by the Torchwood actress Cush Jumbo about the world’s first black female celebrity. Josephine Baker was born to wow the crowds. A child cabaret artiste from St Louis, she performed as a chorus girl in New York and then leapt the Atlantic to become the toast of Paris in the 1920s. Aged 19, she was one of the biggest theatrical stars in Europe. She married an Italian count, adopted 12 children, bought a château, went bankrupt, fought for the Resistance during the war, returned to America in the 1950s and became a heroine of the civil rights movement.

Cush Jumbo brings a formidable range of skills to the role. She dances with furious gusto. She sings powerfully and sweetly and she has tons of stage presence. The trouble is she’s not that interested in Josephine Baker. Cush Jumbo is a Cush Jumbo fanatic, and she constantly interrupts Baker’s story to drag us back into the threadbare drudgery of her acting woes and her boyfriend gripes. This dual approach smudges the show’s focus and wrecks its momentum. And it makes spectators feel deceived and practised upon. A corny trick is employed to convince us that Jumbo is facing a dilemma which unfolds during the performance. She arrives on stage late, and distracted, and claims to have been busy at a casting session that may result in a big showbiz break. She checks her phone regularly to see if her agent has received the all-important news. This dippy prank works, just about, at a fringe theatre. But if the show transfers into town, the trick will self-destruct. A solo performer starring in the West End can hardly be awaiting make-or-break news from her agent.