First Night: Wicked, Apollo Victoria, London

The broom is such a convenient method of transport these days, given the rigours of airport security. And now flying across the Atlantic astride one such vehicle comes Wicked, a musical prequel and sequel to The Wizard of Oz. Adapted by Winnie Holzman from the 1995 novel by Gregory Maguire, the show - which has music and lyrics by Stephen Schwartz - delves into the back story of the Wicked Witch of the West. In New York, it quickly recouped its $14m (£7.4m) capitalisation costs. There are further productions springing up in major cities and a touring version. On the other side of the pond, there is no rest for Wicked.

It was hard to tell from last night's first night how well it would go down here. The audience was so papered with connected people that everything was greeted with uniform ecstasy. Green-faced and in hideously clashing student clothes, Idina Menzel had merely to walk on stage, as Elphaba, the future Wicked Witch, and the roof came off. A friend who'd seen the show in New York told me that this girl can out-sing Streisand. I beg strongly to differ. Her voice is certainly power-packed and tuneful but it is also featureless, lacking Streisand's range of emotional colours.

The first half of Wicked is, however, a bit like the real-life Streisand story translated to Oz and with added chlorophyll. Girl has distinctive feature that makes her an outsider and the butt of taunts. Then she finds that she has wondrous powers (here discovered with the help of a book of spells at magic school) and soon leaves everyone literally standing as she sings of singular flight. Here it's on a broom rather than on a ship. I confess that my tummy lurched pleasurably during the evening's big uplifting number, "I think I'll try/Defying gravity".

The Wonderful Wizard (a very poor Nigel Planer) is exposed early on as fraudulent coward, who because he can't read his own spell-literature, has to unite the country by demonising sections of the community - animals, Munchkins etc. The attempt at topical political allegory is well-meaning but also melodramatic, incoherent and dreadfully superficial. Entangled with this is the story of Elphaba's troubled with her Legally Blonde-style friend and future Good Fairy from the South, Glinda (Helen Dallimore) and their rivalry over the apparently airhead dish, Fyero (Adam Garcia).

I enjoyed very little apart from the delicious Miriam Margolyes, all embonpoint and Barbara Cartland face as Madame Morrible, mistress of the magic academy. The songs sound like dozens you've heard before. The acting is, by and large, appalling. The book is aimed uncertainly at several constituencies. The production manages to feel at once overblown and empty. As the crowds heaved up for air during the interval, a lady next to me asked: "Are you liking it." "I'm afraid I'm not," I replied. There was a ghastly pause. "Well everyone else is!" she barked. I fear the show's message about the need to assert the right to be different may not be getting across.