Acrobat auditions begin with a strength test - climbing a rope using arms alone. "Once they are up there, we ask them to sing a song," says Cantin. Such requests nonplus athletes, but they are judged on their willingness to risk dignity for the sake of entertaining an audience.

More rigors follow. Whether ballerinas, tumblers, singers, dancers, or martial artists, only one in six make the grade.

Each year, between 50 and 60 acrobats enter basic training under head coach Philippe Aubertin. Aubertin spends four months making entertainers from athletes, meanwhile teaching them circus-specific equipment such as the Russian swing, a rotating suspended platform. But the toughest trick: learning to please an audience instead of earning points from judges. "Here, there are no rules, and they're a bit lost sometimes," says Aubertin, gesturing at a vast gym where recent recruits, most from Eastern Europe, practice basic routines amid a gabble of languages.

In a smaller adjoining studio, another recruit learns about makeup. Cirque troupes have no makeup artists. Each performer applies his or her own greasepaint in designs sometimes verging on the bizarre. This woman has had half her face painted in a whorl of gaudy bands. She'll now do the other half. Next time, she'll do it all herself. Within a year of training, little more than half the recruits adapt to this new circus world well enough to receive standard two-year contracts on Cirque shows, Aubertin says.

RELIABLE SYSTEMS for making costumes and training performers are one thing. It's harder to see how Cirque du Soleil has maintained its remarkable originality for two decades while selling out performances in many different places and cultures. Five years ago, the creative process went through major upheaval. The group that had designed all previous shows was taken off the job, and Cirque started reassembling ad hoc teams of outsiders to create each new show. Lyn Heward, chief operating officer for creative content and a Cirque employee for 12 years, says the process starts with recruiting several highly talented, highly diverse entertainers and giving them complete creative freedom.