South Pacific, Barbican Theatre

"Whoring after the public taste" is how Ingmar Bergman described some rather funny hanky-panky in one of his most singular films. It's what showbusiness thrives on, and it's fine if done well. Yet a decade ago Trevor Nunn crowned the National Theatre's trio of keenly observed Rodgers and Hammerstein stagings with South Pacific characters of flesh and blood, as its creators had surely envisaged. Here, despite strong delivery of a string of hits and fluid, evocatively lit designs, Bartlett Sher's Lincoln Center Theater revival too often takes us back to the Broadway whorehouse.

Admittedly the dodgy dramaturgy, forged from Michener's Tales of the South Pacific by Hammerstein in league with original director Joshua Logan, makes keeping it real difficult. Very well, the wartime South Pacific background throws into relief issues of miscegenation - but featuring an underage Tonkinese girl who hardly says, let alone sings, a word - and age differences, but who cares much, until it's almost too late, about the cardboard charm of the Frenchman loved by a hick from Little Rock? And as we move towards Nurse Nellie's shock-horror reaction to her Emile's two little brown children, you can't help feeling R&H had run into trouble when they start wheeling out the reprises as early as a first-act finale.

More solid evocation of the 1940s period - which we got in Nunn's production, but not from Catherine Zuber's costumes here - would have helped to stress our heroine's credentials as a carefully taught mess of prejudice. But more worrying is the stiff, to-audience vaudeville style so often adopted by Sher, who gets his singer-actors to semaphore but not to seem at ease in their bodies or with who they're supposed to be. It clearly didn't help that Samantha Womack was gamely battling on with a broken toe; difficult to deliver the exultant waltz song of "I'm in Love With a Wonderful Guy" when you can't fling yourself about with gay abandon. But Paulo Szot as the suave plantation owner should not have been encouraged to endear himself to the audience with a few anachronistic gags when we're only just getting to know our young and middle-aged lovers as credible individuals. And you never sense the dormant volcano that led this De Gaullist to kill a man back in his French village.

Never mind; Szot (pictured right) has the right oaky, operatic baritone to follow after his own fashion in the footsteps of true basses Ezio Pinza and Giorgio Tozzi, and so should his eventual successor Jason Howard. The showstopper is another waltz, "This Nearly Was Mine", throbbing with Broadway emotion but scaled down for the softest of reprises. It's also admirable that Lieutenant Cable should be a tall show singer with a solid tenorial top, Daniel Koek (pictured below with a virtually mute Elizabeth Chong); "Younger Than Springtime" as delivered to the passive Tonkinese teenager he's immediately slept with regains some of the charm here.

The girl's pushy mother, wily Bloody Mary, is ideally incarnated by Loretta Ables Sayre of the original Lincoln Center production; the character gets to do the whole-tone mystery act of "Bali Ha'i" as well as the more charming-native numbers, but how much more interesting the stage Bloody Mary would have been if Hammerstein had carried over Michener's picture of her as a fighter for native rights (as, by his account, she was in real life). Womack has some style, and what sounds to me like an authentic Arkansas accent but a rather insecure upper register. And having now seen clips of Kelli O'Hara in the original Lincoln Center Theatre production on YouTube, there's no comparison; this music is in O'Hara's system as it never will be for Womack. The minor roles make little impact (surely Sher's fault), with the exception of Nigel Williams's robust Captain Brackett. The sailors sing lustily and somersault about but remain showboys for all that, and Emile's sweet kids as well as his servant aren't exactly Polynesian, though I guess you could stretch a point and say they're from the Solomon Islands.

What keeps us engaged even through the duller stretches of the action - though we can thank our lucky stars that the war stuff is kept to a minimum compared to its ekeing-out in the movie - are the flexibility of Michael Yeargan's always handsome set and the colours thrown on it by Donald Holder's lighting, from phosphorescent sea to the darker clouds gathering in Act II. And of course those songs, though unevenly distributed, are gems one and all - though more than usually extractable from their context, which may explain their continuing popularity outside the musical. We're lucky to get so much of Robert Russell Bennett's original arrangements from the 24-piece orchestra, reasonably peppy under Jae Alexander and not over-miked. And what a difference it makes, in showzone, to hear a real rather than a synthesised harp. But it's a cruel world where a show like this gets showered with Tonys and a much more sharply observed musical staging like Lend Me a Tenor closes prematurely despite standing ovations night after night.

• Book tickets for South Pacific at the Barbican, running to 1 October
• Screening of the film South Pacific at the Barbican on 2 October
• Read theartsdesk's feature about the making of this production

A whole different ball game: Kelli O'Hara in the original Lincoln Center Theatre production

Paulo Szot sings "This Nearly was Mine"