What's the appeal of flash mobs? Canadian choreographer Matjash Mrozewski thinks it might be the endorphin-boosting power of moving in unison with a large group, in the way a singer might feel within the swell of a chorus. Having set two consecutive flash mobs on hundreds of people for International Dance Day—"a bit of nail-biter," he says—the 36-year-old dancemaker knows a thing or two about them. 

But Mrozewski does not want to be known as the Guy Who Does Flash Mobs ("at least, not for less than $500," he jokes) and considering his breadth of work, he shouldn't be. A former National Ballet of Canada dancer, he has created work for classical and contemporary companies worldwide, as well as choreographing for film and runway. Right now, he's making his Oregon Ballet Theatre debut with The Lost Dance, a new work for seven dancers. 

He doesn't want to say too much about the piece, but he does drop a few tantalizing hints. It will be a contemporary ballet with elements of social dance. It will be edgy and a little mysterious. He has worked with composer Owen Belton on an atmospheric score layering elements of rock, blues and pop music. And local designer Adam Arnold is providing clothing with a vintage vibe. Challenged by OBT Artistic Director Christopher Stowell to step out of his comfort zone of duets, Mrozewski is paying special attention to arms and hands, which he feels are underused in ballet. 

The Lost Dance will appear on OBT's Chromatic Quartets program alongside Christopher Wheeldon's lyrical duet Liturgy, George Balanchine's tricky neoclassical ensemble piece, Stravinsky Violin Concerto, and Val Caniparoli's genteel balletic safari, Lambarena. Mrozewski thinks it's a good mix; he describes his place in it, cautiously, as a classicist. "I like form. I like structure. I like some restraint," he says. That said, he thinks what ties his disparate work together is a desire to catch a glimpse of humanity: "I don't like doing movement just for movement's sake," he says. "I want to see that there's a person doing it."

SEE IT: Newmark Theatre at Portland Center for the Performing Arts, 1111 SW Broadway, 222-5538, obt.org. 7:30 pm Thursday-Friday, April 19-20; 2 and 7:30 pm Saturday-Sunday, April 21-22; 7:30 pm Wednesday and Friday, April 25 and 27; 2 and 7:30 pm Saturday, April 28. $23-$140.