At Tuesday’s after-school rehearsal of the wildly popular Andrew Lloyd Webber musical "The Phantom of the Opera," Punahou School senior Jasmine Stiefel was in costume for her role as Christine, the young singer mentored by the disfigured fiend. She and the rest of the cast, crew and student orchestra had just finished a run-through of the musical’s first half.

"This is immense," said Stiefel, who will share the demanding role on alternating nights with Adriana Hernandez. "I was in last year’s production of ‘The King and I,’ but this is my first big role in a musical. It’s very exciting."

"Exciting" might be an understatement, considering the large and complex production Punahou’s theater program is undertaking as one of the first schools in the country to stage the smash musical. Licensing for the Webber production first became available to high schools and colleges over the summer.

"We e-mailed our application for doing ‘Phantom’ on June 3 and got the go-ahead contract a week later," said technical director Brian Gilhooly. "Since the third week of August, we started set construction."

There was still a bit of detail paint work to be done on the set Tuesday, the lighting design hadn’t begun yet, and the boat (a reworked mobility scooter for the elderly) that is used by the Phantom (played by Miles Provencher) to take Christine through the sewers of Paris was still not dressed. But the immense multipurpose stage pieces were in place, as was the all-important chandelier constructed with the help of Diamond Head Theatre.

Come opening night Thursday, all that will be needed is a bit of added on-stage magic provided by the 75-student cast and the musicians and crew, with the help of Gilhooly, music director Mike Lippert, costume director Vickie Van Wagner, choreographer Tony Young and director Paul Palmore, who also will be doing the singers’ wireless microphone sound mix during the musical’s two-weekend run.

"This is the most technically difficult play that the school has done," Palmore said. "There are so many scenes, and much of the transitions happen in front of the audience, so we’re coordinating large set piece moves that can happen as quickly as 30 seconds. But we’re doing this to the best of our ability. … Obviously, ours is not as elaborate as the original Broadway production but, still, I think ours can be just as good.

"We figure the kids can pull it off, with a little pushing and prompting."

Other principals in the cast besides Provencher, Stiefel and Hernandez include Lea DiMarchi as the diva Carlotta and Jack Morrison as Raoul, Christine’s childhood friend and fiance.

(When Morrison and Stiefel had to share an on-stage kiss, most of the cast peeked curiously from the wings and behind the backstage set. Palmore later playfully chided them about it and reminded the group not to try that during the performances.)

"As a ritual, I give the cast a 15-minute talk before each performance," he said. "It helps them keep their focus and keep as mature as possible. Sometimes I think it’s difficult for them to see how big a deal this musical is, and I want to remind them that each one of their contributions is valued and important to the success of this.

"I love the kids and I think they will do a great job," he said.