A major attraction of this week's touring production of Rodgers and Hammerstein's South Pacific is seeing how young Helena Blackman - runner-up in the TV reality show How Do You Solve a Problem Like Maria? - copes in its starring role.

Pretty damned well, is the answer.

While she just missed out on grabbing the part of the musical stage's most famous nun, she makes a splendid job as its best-known nurse.

Admittedly, she takes a somewhat cautious approach to aspects of the role of Ensign Nellie Forbush, suggesting perhaps an exaggerated determination to get it right.

But there is no denying the warm sympathy she provokes in the audience through Nellie's winsome gaucheness - nor her impeccable handling of the wonderful numbers she gets to sing. Her success, I feel sure, has much to do with the close rapport she has clearly developed with the enormously experienced Dave Willetts, the only man to have played the major roles in both Les Misérables and The Phantom of the Opera.

He gives a moving portrait of the ageing French planter Emile de Becque who, having loved and lost a native girl in his Pacific paradise, now seeks happiness with the lass from Little Rock, Arkansas.

This being the mid-1940s, during the Second World War, racial prejudice naturally rears its head to threaten their relationship.

Its dark shadow is similarly cast over the love that develops between Lieutenant Joseph Cable (Ian McLarnon) and the native girl Liat (Kanako Nakano).

This is a huge disappointment to her mother Bloody Mary, wheeler-dealer to the US forces occupying her idyllic island. As performed by Sheila Francisco, her songs Bali Ha'i and the hugely infectious Happy Talk are highlights of the show.

There are, of course, so many more glorious numbers - including Some Enchanted Evening, There is Nothing Like a Dame, Younger Than Springtime and A Cockeyed Optimist.

Today's melody-lite musicals pale in comparison.

But while melody is in copious supply, so too is plot. Novelist James Michener, who provided the story, said the translation from stage to page had been made "without mussing an eyebrow of one of my characters".

There are times, however, during a longish (nearly three hours) evening when you start to wish Rodgers and Hammerstein had not been so meticulous.

The gallery of characters seems over-extended to the point of creating confusion, and the twists of the tale are sometimes hard to follow, partly here as a consequence of the mushy quality of the sound.

But it is still a wonderfully rewarding evening, and certainly not to be missed. It runs until Saturday.