theartsdesk MOT: Wicked, Apollo Victoria Theatre

Wicked is that rare Broadway musical transplant to London that has recouped its costs - and how.

Part paean to female empowerment, part parable of life in Bush-era America or any land on the desperate look-out for an enemy, the show also offers spectacle a-plenty amidst a musical theatre climate increasingly defined by the Menier Chocolate Factory and its various progeny, whereby less is more (which, in fact, sometimes it is).

How then is this speculation on the state of Ozian affairs prior to a certain iconic film - hint: think yellow brick roads and Toto - holding up as it enters its fifth year at the Apollo Victoria Theatre this autumn? Very well indeed, in fact, at least if a packed-out weekday performance is any guide, the cast all present and accounted for at a time of year when holidays and a slackening in commitment among some companies can be rife. (On Broadway in the summer, understudy slips tend to tumble out of playbills like so much confetti.)

The audience, too, sat rapt through the nearly three-hour show, rising almost as one when the two tireless leading ladies, Louise Dearman and Rachel Tucker, took their bows. Frankly, here at last are the attentiveness and respect that have gone missing from several of the (glorious) Proms I have caught this year, a once-hallowed environment that seems to have succumbed to the creeping virus of the fusspot fidget and the hacking cough. Perhaps this musical's avid fan base could teach the Albert Hall denizens a thing or two?

Indeed, it's fascinating to revisit Wicked this many years after its Broadway and London premieres to witness to what degree the piece has exerted an influence on shows that have come since. Surely Elle Woods's anthemic self-assertion in Legally Blonde belongs to the post-Wicked school of women staking their claim to the musical theatre spotlight. (Yes, I know the 2001 film of Legally Blonde preceded Wicked, but the stage musical is its own entity.)

This particular continuum stretches back to Mamma Mia!, a show in which women of a certain age get to party down and rock out, relegating the men in their orbit to the sidelines. The equivalent in Wicked is that an erstwhile talent show star and West End pin-up, Joseph and the Amazing Technicolor Dreamcoat's semi-clad, curly-haired Lee Mead (pictured right), here plays (very agreeably) third banana to two women who are far less well-known than he is.

Wicked offers some juicy supporting roles, and they are well taken by the current ensemble, most of whom took over at the end of March. (Mead joined a bit later as the shallow prince, Fiyero, a character on apparent loan from Into the Woods who learns not only that things aren't black and white but that true love can be green.) Julie Legrand thankfully downplays the camp that informs every malevolent bone of Madame Morrible, the part with which Miriam Margolyes all but upended this show on press night, and George Ure makes a sweet-faced, firm-voiced Boq: male half of the secondary love interest that includes Nessarose (a commendably fierce Cassandra Compton), younger sister to Elphaba, whom most of us know merely as The Wicked Witch of the West.

But any Wicked stands or falls both by its Elphaba, she of the attention-grabbing verdigris, and by her Shiz school adversary-turned-eventual-best mate, Glinda (née Galinda), whose blonde locks exist to be tossed in much the same way that language, at least as chirruped by Glinda, is there to be mangled - usually by adding syllables where they didn't exist before: "confusifying", and the like.

Kristin Chenoweth originated the role on Broadway and is likely to remain definitive in a part that can seem smug or fatally self-absorbed in lesser hands. To her credit, Louise Dearman's current Glinda at the performance caught earned several spontaneous rounds of applause, indicating the appeal of a ceaselessly perky goody two-shoes who learns what it actually means to be good. Dearman, too, looks genuinely at home in the bubble from which she wafts toward and from the stage, the (literally) above-it-all golden girl who ends up befriending an outsider, Elphaba, whose primary misfortune was to be born of a different hue. (Find in that what resonances you will.)

And Rachel Tucker, the Belfast native who reached the semi-finals of the BBC's I'd Do Anything reality TV competition, grounds "Elphie" in an almost feral conviction that makes her ascent at the first-act finale on "Defying Gravity" a thrilling piece of acting, not just an exercise in lung capacity. (On this evidence, Tucker's would appear to be considerable). She delivers the pop ballads of Stephen Schwartz's critically undervalued score with power and purpose but is even more telling at quieter moments - her sotto voce finish, for instance, to "I'm Not That Girl" containing within it a hard-won acknowledgment of heartache.

Incongruities remain, not least a Wizard (now taken by Clive Carter, late of Priscilla, Queen of the Desert) whose essential benignity, however anticipated by the 1939 movie, is at notable odds with the proto-fascist state over which he presides, and the occasional Vegas-style scale of the thing - you want bang for your buck? here it is - doesn't entirely mesh with the story of someone revealed to be a political agitator as well as a lover and a friend. (Free those monkeys now!)

Or maybe therein lies Wicked's true subversiveness: that it packages its politics within the context of musical firepower that may or may not make you realise the degree to which Glinda at times seems an awful lot like Sarah Palin, though I'm not sure Hillary Clinton would appreciate any comparisons to Elphaba. Realpolitik, though, rarely comes with the dual hymn to the sisterhood that is this show's eleventh-hour number, "For Good", which is another way of pointing out that, like the giddier of its two heroines, Wicked knows a thing or two about how to be popular. And with Tucker driving the production as if Elphaba's very being depended on it, a potentially soulless mega-musical machine now seems deeply personal, as well.

• theartsdesk guide to the best musicals in London