The cast of High School Musical thrill fans at the Air Canada centre last night. The touring version of the musical grew out of the hit Disney TV movie. (Craig Robertson)

TORONTO - No one is more shocked by the success of High School Musical than the cast members.

"None of us were expecting this and that's the coolest part," said Ashley Tisdale, who plays Sharpay in the High School Musical concert tour, which invaded a soldout Air Canada Centre last night.

"In this business, you never know. But this is the best way it could have happened."

High School Musical began as a made-for-TV movie on the Disney Channel in the United States last year, but young-teen and pre-teen audiences took to it immediately. It spawned a triple-platinum soundtrack CD and has inspired a whirlwind concert tour, which began in November and wraps up at the end of this month.

"When they first said 'arena tour,' I had no idea what that really meant," said Lucas Grabeel, who plays Ryan and was one of six cast members interviewed yesterday afternoon. "They said '15,000 people,' and I said, 'I don't even know what that's supposed to look like.' "

Corbin Bleu, who plays Chad, pointed out that most Disney movies find a core audience. But if you have children or siblings in the target age group, you already know that High School Musical has hit an entirely different level.

"For all of us at the start, it was just another Disney movie, another project," said Bleu, who will star in Jump In!, a forthcoming Disney movie that was filmed in Toronto last summer. "But all of us are going through this strange phenomenon together."

The High School Musical concert features songs from the movie as well as solo material from Bleu, Tisdale and Vanessa Hudgens (who plays Gabriella). The only major cast member from the movie who is not on tour is Zac Efron, who has been replaced by Toronto native Drew Seeley (see sidebar).

All the main cast members have theatre experience, so they are not out of their element performing live. In fact, Hudgens told an amusing story about how far the cast will go to connect with an audience.

"The other night there was this teenage couple in the front row and they were acting like it was a drag to be there," Hudgens said. "Both Ashley and I sing ballads, so we were singing right to her boyfriend and she was so angry at us. But it was fun. Things like that motivate you to get people more involved."

With most of the frenzied fans, involvement is not an issue.

"We're enjoying something a lot of performers don't get to have, but we know there's a deadline," said Monique Coleman, who plays Taylor and also was a competitor on Dancing With The Stars last season.

"We know that on Jan. 29 it all will be over. We're just living this moment and doing the best we can."

Musical brings Seeley full circle