At various times over the last three years, in Canada, Australia, America and Ireland, a very special dance has been set in motion.

Entire rooms full of revellers have launched into spontaneous displays of the alphabet-shaped choreography that accompanies evergreen 1970s disco smash, YMCA. This song, made famous by The Village People, a group of young men extravagantly dressed up as various macho archetypes, may be a staple of late-night clubland cheese-fests across the globe anyway, but this is different.

The extrovert activity described above exploded out of Dance Marathon, a four-hour participatory endurance test-cum-Dionysian rite cum-life-changing piece of social engineering devised by the Toronto and New York-based experiential theatre explorers, bluemouth inc.

As Dance Marathon shimmies into Edinburgh for a limited run as part of the Traverse Theatre’s programme, the show has proved so apparently transformative for its audience that playwright David Greig, no slouch himself in the creative stakes, was moved to describe it as “a new paradigm in performance”. Greig went on to highlight the piece’s final moments as “one of the most beautiful and moving things I have ever seen in a theatrical performance.” High praise indeed for a show in which the audience effectively do much of the work, but what is it that makes Dance Marathon so special?

“It’s the taking part,” according to New York-based Stephen O’Connell, one of the bluemouth collective’s core team. “People are disappointed now if you ask them to sit in a dark room and be passive. But there’s something there about the dance itself, and how it affects our bodies.

“In our twenties we’re going to clubs and dancing, and we’re in our bodies a lot, but something happens when we get to a certain age. Now, for me, outside of doing it professionally, the only chance I get to dance is at weddings. Dancing can transcend us, but we can get disconnected from it, but when you get back in touch with it, amazing things happen.”

O’Connell points to Dance Marathon’s YMCA moment for proof.

“That moment is so silly and so ridiculous,” he says, “yet everybody does it without thinking, and there’s something exciting about that euphoric sense of communal transcendence. It’s really quite profound to watch.”

Dance Marathon, then, is an epic example of the trend for a more immersive kind of theatre that puts the audience close enough to the action to become a part of it. Both Ontroerend Goed’s Audience and Adrian Howells’ May I Have The Pleasure..? are examples of this, and bluemouth cite Punchdrunk’s labyrinthine exercises in interactive theatre as well as Forced Entertainment’s own endurance tests as influences.

Beyond such avant-garde peers, Dance Marathon’s roots go back to the real-life competitive endurance tests of the 1920s and 1930s American recession era. These events could often go on for days or even weeks, as documented in Sidney Pollack’s 1969 film, They Shoot Horses, Don’t They, based on dance marathon bouncer Horace McCoy’s 1935 novel of the same name. They provided a roof and food for down-at-heel entertainers as much as others on the skids. Where those original dance marathons also provided titillating spectacle for audiences in need of kicks, bluemouth’s take on things is much more democratic, inclusive and feel-good in nature.

“The beauty of a dance marathon is that it’s really inclusive,” explains singer and performer Ciara Adams, another bluemouth core member based in Toronto. “You won’t ever be singled out as an individual, and we don’t want to make anyone feel uncomfortable. It’s more about the entire group in that we’re trying to make an instant community. We won’t ever know everyone’s experience, but everyone has a story and seems changed in some way.”

Originally founded in Montreal, since bluemouth inc decamped to Toronto in 2000, the five-core collective have produced multi-discipline site-specific locations that have included a network of hotel rooms and a Canadian wood. The relationship between performer and audience has been crucial to the company’s ongoing line of enquiry. Dance Marathon, however, was a major leap into the unknown.

“We’d done a show in which the audience took part in a softball game, and having the audience become participants was a significant shift in our thinking. At first we thought we might do a 24-hour show, and that developed into early workshops for Dance Marathon, which we invited 20 friends to come in while we performed around them. They told us afterwards that it was a missed opportunity, and we realised that this show wasn’t going to be about us, but about the audience’s own experience,” says O’Connell .

For each show, bluemouth intersperse the audience with 20 local dancers, with assorted turns being performed throughout to a live band overseen by an MC. With strangers meeting for the first time on the floor, as with a real dance marathon, there will be eliminations, and, eventually, a winner. If any of this sounds at all daunting, think again. Because, as bluemouth have consistently discovered, as long as the invitation to join in is set up right, the audience will fling themselves feet first.

“The learning curve for all of us has been so steep over bluemouth’s 10-year history in terms of how receptive people are and how intelligent people are and how things have to work out,” says Adams.

“If the MC speaks too long, people are going to get bored, so we have to say less and do more, and learn how to shift the energy on to the next thing in a way that people don’t even notice it.”

As O’Connell and Adams have seen first-hand, Dance Marathon speaks volumes about an audience’s desire to join in the creative process, and the current trend for experiential works great and small seems to bear out the company’s instincts. While good old-fashioned black box theatre with fourth walls well and truly intact isn’t going to go away in a hurry, are dance Marathon, Audience and May I Have The Pleasure..? the future, or just a creative blip that runs alongside the social disenfranchisement recession culture brings with it?

“I’m really curious to see if it’s a trend,” says O’Connell. “I certainly see a lot more immersive work now, and I’m curious to see if the sort of paradigm shift that David Greig talks about actually happens.

“For us it’s always been about making work that’s exciting, and creating some kind of sense of intimacy among the spectacle, and seeing how far we can go with that.”

Adams goes further. “With Dance Marathon we’ve really had to challenge ourselves in terms of ego,” she says, “and that’s not always been easy. But in terms of the sort of thing that’s going on in Dance Marathon, I don’t think we know yet how far it can go. I think this sort of work will evolve, and I think it will be important, but it’s not as if every piece of art is going to be immersive. Having said that, immersive and experiential work is starting to reach the mainstream, so who knows where that will take things.”

Dance Marathon, Traverse Theatre@ Lyceum Rehearsal Room, August 3rd-14th

www.traverse.co.uk