It's hard to believe that Hayley Mills, the perennial child star of all those Disney live-action films, is old enough to play Anna Leonowens, the matronly Victorian teacher who has a platonic romance with the king of Siam in The King and I. In some ways, though, it's not so big a stretch from Pollyanna to "Whistle a Happy Tune." Ms. Mills is still keeping her chin up.

The Dallas Summer Musicals brings the popular Rodgers and Hammerstein show to town Tuesday for almost two weeks. The Broadway version won a Tony Award for Donna Murphy last season in New York, as well as raves for her recent Broadway replacement, Faith Prince. But it was actually designed and staged for Ms. Mills, now 51. She opened it at Australia's Adelaide Festival in 1991 and toured that country with the show for more than a year.

"It was one of those irresistible things," Ms. Mills says. "It was suddenly dangled in front of my nose, like ornaments on a Christmas tree."

She loves the gaudy purple-and-gold sets by Australian opera designer Brian Thomson, which also walked off with a 1996 Tony. The details reflect Thai culture much more than previous versions.

"As far as production values, I think this is much more interesting," Ms. Mills says. "It really echoes the period."

But what really interests her about The King and I is the conflicts it portrays.

"It's still a very thought-provoking piece - that's part of its enduring quality. Even after you've left the theater, you find yourself realizing what an enormous amount of meaning there is in it. It's about the head-on confrontation between East and West, between men and women," she says.

Ms. Mills says she regrets not having seen Ms. Murphy - whose take on the role was darker and more serious than most Annas - or Ms. Prince in New York. In any case, she has tried to approach the role freshly this time around, even though she's already spent more than a year of her life doing it.

"There's a fascinating alchemy in bringing new casts together. You can see the same work many times and find something new with each set of performers," she says.

Her new leading man is Vee Talmadge, a director and playwright as well as an actor. Like Lou Diamond Phillips, who played opposite Ms. Murphy, he brings a younger, earthier persona to the king than Yul Brynner, who owned the part for decades.

There has to be chemistry as well as alchemy in casting The King and I, because the show is the story of a love affair, even if it is unconsummated. The king hires Anna to come from England to teach his many children. The headstrong monarch and the equally hardheaded teacher sometimes disagree violently. But the respect they gain for one another blossoms into something strangely romantic.

Of course, much of this story is told in song and dance. The score's famous tunes include "Hello, Young Lovers" and "Shall We Dance?" One of the show's highlights is Jerome Robbins' choreographic version of "Uncle Tom's Cabin" done in Asian dance steps; Lar Lubovitch has done additional choreography for this production.

Ms. Mills says the singing is her biggest challenge.

"I'm not really a singer, you know. I do it my way. The last time I did a musical [before the Australian tour] was 1970, though I've had singing lessons for years and years," she says.

She has drawn her inspiration from Gertrude Lawrence, the famous British star who took the book to Rodgers and Hammerstein and asked them to create a musical for her. Ms. Lawrence's voice was not your normal soprano's.

"I knew instantly I wasn't going to sing like Marni Nixon," Ms. Mills says, referring to the legendary Hollywood singer who provided the soundtrack that Deborah Kerr lip-synched in the movie.

The real enemy is fatigue.

"This is a long show, emotionally demanding. It's hard work, singing and all that dancing and all that shouting at the king," Ms. Mills says.

"Also, in this beautiful country, you do four shows on the weekends. That really wears you out."

To stay in shape, she has to avoid smoking altogether, and it's almost the same with drinking.

"Sleep is the most important thing of all," she says. "And I have cut out milk from my tea, which for me is a big sacrifice."

DETAILS

WHAT: The King and I, presented by the Dallas Summer Musicals

WHERE: Music Hall at Fair Park

WHEN: July 8 through July 20, with performances Tuesday-Saturday at 8 p.m. (added show July 13 at 8 p.m.) and matinees Saturday-Sunday and July 17 at 2 p.m.

ADMISSION: $7 to $50.

© 1997 The Dallas Morning News