Photo By Al Seib

Philippa Hayball, here playing "Target," has extended a dance career by joining Cirque du Soleil.

As a theater critic, I see a lot of amazing things onstage, but Cirque du Soleil's Quidam was a new experience for me. Combining circus conventions, acrobatics, music and a strong sense of theatricality, Quidam is a hybrid that moves into the realm of emotion, image and pure satisfaction.

Quidam is a Latin word meaning an "anonymous passerby." He's a character out from a Magritte painting, a headless overcoat carrying an umbrella and a bowler hat. He passes his hat to Zoé (Tori Letzler), a teenager bored with her preoccupied parents. The hat transports her to a world of wonder, full of strange and mind-expanding sights.

OK, it's a pretty flimsy concept, but it establishes a dreamlike environment for the cast of 51 performers who are constantly in motion, often wearing white coveralls (looking for all the world like HazMat suits) to move things or become a bit of living scenery. Sometimes they're characters at the periphery of sight -- a ballerina doing pliées, a clown tumbling -- enhancing the dreamlike atmosphere.

The Grand Chapiteau (a lesser circus would call it a "Big Top") that houses the performance adds to the feeling. It seats 2,544, only a few seats less than the Aronoff Center's big hall, but it feels more intimate: The seats surround the thrust stage like a horseshoe, so everyone is close. Overhead is a 120-foot conveyor bridge that is both a grid for lights and a mechanism to fly performers forward and suspend them above the stage and the audience. The ceiling of the tent is decorated with projections of clouds.

Within this magical atmosphere, audiences see performances more breathtaking than death-defying (although most of what you see are things you shouldn't try at home.) Right off the bat you're astounded by Cory Paul Sylvester's work as a spoke in a "German wheel," kept moving and spinning while he does somersaults and acrobatics, stopping just short of rolling into the audience. Four little girls from China spin diabolos, a kind of yo-yo they fling in the air, catch on a string and pass back and forth -- while doing flips and gymnastics.

Performers hang, twist and turn while suspended by silk banners, dangling ropes and a rope trapeze. A team of 15 perfectly synchronize acrobats toss and flip one another effortlessly (three men standing atop each other's shoulders have a fourth flipped to the top). Another group of 20 elevate rope skipping to an art form, both as high speed individuals and as intricate patterns for the entire group. Olga Pikhienko perches on narrow balancing canes and makes intricate moves; Jérôme Le Baut and Asa Kubiak move slowly and deliberately through amazing positions of partnered strength and balance.

Even the audience gets into the act. Everyone is shaking their heads, of course, amazed a bit more by each act. But at several points cleverly understated clowns -- an odd scarecrow of a ringmaster (Mark Ward) and the expressive Ambroise Martos -- bring audience members onstage. Ward "helps" with pre-show seating. Martos takes a pretty young woman on a romantic car ride in Quidam's first act; in the second act, he shoots a melodramatic silent movie with four "actors." The clowns' ability to roll with amateurs and build on their hesitancy adds humor.

The wonder of Quidam is not just its precision and its imagination, but its universality. Six musicians provide accompaniment (occasionally too amplified), and there's some singing (in French, I believe), but it's more part of the atmosphere than something you listen to closely or understand. Afterwards, it feels like awakening from a pleasant dream of disconnected images -- and an urge to sleep and dream again. A Cirque rep told me that once a city has hosted a performance, more can be expected in the future. That's great news, but not a reason to miss Quidam. Get a ticket now. Grade: A