TORONTO - When the smash musical "Billy Elliot" opens in a new city, it's usually a star-studded event. Bob Geldof and Hugh Grant were at the London debut. When the curtain came up on Broadway, Woody Allen and Rosie O'Donnell turned out. In Chicago, Oprah Winfrey and Jesse Jackson graced the audience.

Oh yes -- and the show's producer David Furnish and his partner Elton John, who wrote the music, usually drop by for a new opening too.

The superstar couple is expected to be on hand when "Billy Elliot" has its official Toronto premiere on Tuesday. But no matter who attends the show on opening night and onward, don't expect many jitters from the uber-poised young actors in the show.

"My first big nervousness was when I first did 'The Nutcracker' in 2009 with the National Ballet of Canada," says 13-year-old Marcus Pei, one of four actors who shares the role of Billy.

"I remember looking in the audience and I was so scared. That kind of almost prepared me for 'Billy Elliot' because I already knew what it felt like to perform onstage in front of a large audience."

Another of the Billys, 14-year-old J.P. Viernes, says the first time he felt really rattled was when he had to run-through the show for the directors and creators -- with no audience.

"I just got really nervous about that because it was just them watching us and there weren't people to applaud," says the teen, who hails from Half Moon Bay, Calif., and cut his teeth in the Chicago version of "Billy Elliot" before coming to Toronto.

"In the show, the audience kind of gives you energy."

"Billy Elliot," about a young boy in an English coal-mining town who yearns to become a dancer, has had wildly successful runs in London and on Broadway (where it won a slew of Tony Awards).

It's a physically gruelling show, particularly for the young actors who play the role of Billy.

In addition to remembering their lines and singing, the "Billys" are required to perform an eye-popping array of dance numbers, with styles that encompass ballet, jazz and modern.

"Billy Elliot" has already been in preview performances for several weeks at the Canon Theatre (opening night means that critics are now allowed to review the show).

In a way, Marcus says, the performances are a relief after the punishing preparation period.

"That was probably the hardest part," he said of the rehearsals, noting that he now gets time off when another Billy is performing.

Even though Marcus and J.P. say nerves are not an issue, they still have little rituals they perform each night.

With 18 kids in the cast (including the other two Billys, Cesar Corrales and Myles Erlick), the adult actors in the show have found ways to keep things loose as well.

Marcus says that Patrick Mulvey, who plays Billy's older brother Tony in the show, has a routine he performs each night.

"(He) will come up to me and say: 'lead us to victory' and then we all kind of have our own way of responding to that," says Marcus, who is from Iowa City, Iowa, and has been studying at Canada's National Ballet School since 2009.

J.P. likes to peek out into the audience right before curtain to see if there's a full house. Then, he "prays a little bit" and goes through the show in his mind.

Marcus has his own custom, which he performs right before curtain.

"I kind of do a little mini-ritual in my head," he says.

"I have to think myself through the show and then, when I get backstage and I'm about to come on, I just completely blank out my mind and then I set myself in the character and I go onstage."