Sydney Aryadarei, 10, spent her summer vacation inventing a new dance.

Every week she and her family -- two brothers and both parents -- welcomed Headlong Dance Theater into their small South Philadelphia rowhouse to choreograph a movement and spoken-word performance based on their stories.

"Usually they do it at the theaters, but instead they chose the house theme. That's why they call it 'This Town is a Mystery,'" said the precocious Sydney. "I listen."

Headlong Dance Theater has been creating experimental dance in Philadelphia since 1993, and their newest project uses "citizen dancers," people like the Aryadarei's who have no dance background, but an interesting dynamic between them. For "This Town is a Mystery," Headlong is working with four families in Philadelphia, from a range of backgrounds and neighborhoods, tailoring original choreography for each of them to be performed in their respective living rooms.

"We are creating pieces that are by and about their worlds, their lives, their families, and their bodies," said Andrew Simonet, co-founder of Headlong. "It takes place in their homes, so the audience actually comes to their home to watch the performance. After the performance everyone has a potluck dinner together."

Yes, audiences are required to bring a dish for a post-performance potluck. It is part of the experience, a certain level of intimacy, of going into someone's home.

"If you don't like potlucks, don't come to see this piece," said Amy Smith, another Headlong co-founder.

Smith, Simonet, and their third co-founder, David Brick, all met as students at Wesleyan University, where they discovered dance as a creative medium. They tend to make works that push at the edges of dance, experimenting with radical ways to directly engage the audience, and using common, pedestrian movements that revolutionized modern dance in the 1960's.

"There was a group of choreographers and artists who began to call dance anything that happened with the body in space and time," said Brick, in an interview with "The dance world proper has celebrated that moment and kind of relegated it to a sidebar in the history of dance. Headlong's work has continued this basic idea that a body alive in time and space is as deeply meaningful as a peice of art."

The evolution of Headlong's creative careen has resulted in "This Town is a Mystery," a piece that employs concepts and techniques the company has been nurturing for 20 years. Audience members are not allowed to be passive. They must navigate the city to seek out an alternative performance space -- a residential home -- in perhaps unfamiliar neighborhoods. And bring a dish.

The dancers are put on the spot, too. The non-professional dancers -- of varying ages and abilities -- will have little opportunity to hide as small audiences come into their living room and watch them at perhaps their most vulnerable.

"The strange thing is that dancers and actors -- they seem a little contrived," said Simonet. "They seem to have a humanity that's gone through filters and funnels. Working with these bodies and voices and humans, they are not contrived. The trick is to find what's strong and compelling and human about that, and make it repeatable. Which is hard."

Families have issues. There are kids and their schedules. There are problems, breakdowns and emergencies. There are moods and sibling rivalries. Simonet and company have learned to temper expectations when they arrive at the house for a scheduled two-hour rehearsal. Half of it might be taking up in getting everyone focused, settling a spat, or calming a rambunctious pre-teen. All that family business gets channeled into the dance.

"We've been using those strategies we've been building up over the years," said Smith. "In some ways it incredibly challenging, in some ways it's what we were put on this earth to do."

Video by Lindsay Lazarski