To sample this bizarre collector's item I braved the draughty art deco cavern of the Apollo in Hammersmith on a frosty night, sitting throughout without removing my coat and scarf. Happily, a great blast of warmth emanated from the stage, and the source of that warmth was Katherine Jenkins. Here is a woman who would be a star even if she couldn't sing - but my goodness, can't she just! She can also act, she moves beautifully, and in an incredibly short time has learnt an impressive tap routine.

Also - I almost forgot to mention - she looks absolutely stunning in a succession of glittering, figure-hugging evening gowns. Darcey Bussell, in contrast a slender, ethereal figure, dances beautifully, of course, accompanied as necessary by her ballet partner Jonathan Cope. She also makes a reasonable job of the singing - being miked up her voice can be amplified - but there is something slightly strained, almost old-maidish about her as she wiggles her miniscule bottom in a jazz number.

These are two artists I greatly respect; I have watched Darcey throughout her long career with admiration, but what we have here is, on the one hand, two of the world's most renowned exponents of their separate arts showing us what they can do, and on the other hand, a kind of amateur-night as they try their hand (and feet and voice) in unfamiliar territory.

Bussell's best moments are a flamenco sequence, a dance based on the story of The Red Shoes, and, not surprisingly, a duet as Juliet with Cope as her Romeo. Jenkins shines throughout, but is particularly impressive in an aria from Carmen which she manages to sing while running up stairs and flirting energetically with a series of men. She is moving too as she sings There's a Place for Us from West Side Story, and very funny as she gives us the first song she ever learnt, about eating worms! A pity, though, that she, too, is miked up - I would have preferred to hear that great voice soar naturally out into the huge theatre.

Both stars look good - and by now relaxed - in the Bob Fosse-inspired finale, the only time the whole cast are costumed appropriately for the piece they are performing. The flamenco, for instance, had Darcey in a black cocktail dress, with the dancers looking as though they had been recruited from the nearest bus shelter.

This is a brave try; a strange hybrid containing moments of artistry, but little emotional substance. It is an enjoyable show, but not a show worthy of these two great artists.

Viva la Diva is at Symphony Hall, Birmingham, next week and then at NIA Birmingham on May 7 and the O2 Arena in London on May 10.