We begin at 1,000,000 BC, with a set of scattered household furniture and timer starting at 1,000,000 projected onto the back wall. This begins to drop through the years at pace advancing toward the present day. At around 300,000 BC, Simon Will appears stage left, and begins to step apprehensively around the stage, making occasional awkward eye contact with the audience. He is stark naked but for a blonde eighties wig and a pair of gold knee-high heels. One by one, he is joined by his three co-performers (Sean Patten, Sharon Smith and Sarah Thom) in similar fashion and scant attire. As we enter the twentieth century AD, they begin to pull on garish eighties shirts, frocks and gold leopard-print jeans. They strike a handful of suggestive group poses for the audience. I am adrift with bemusement.

About a hundred minutes later, the show wraps up with a slow motion projection of seven audience members re-enacting a karaoke party. Frank Sinatra plays in the background. I am full of a satiating nostalgia and crying with laughter at one of the audience members on screen grinning smugly into the camera, mouth full with cake. And I’m sure I’m not the only one.

Gob Squad directly explain their intention to re-enact this scene from the off. Their source material is a YouTube video whose subjects are unknown to the company. When they found the video, it had only eight views. It is, they joke, “one of the least watched videos on the internet”. And there’s nothing special about it. Its seven featured characters include Girl Playing on Phone, Woman Eating Cake, and Granny Dancing. It’s ordinary; it’s extraordinary.

The first re-enactment is staged by the Gob Squad performers, but as there are only four of them, it becomes necessary to enrol a cleverly-selected troupe of audience members. Involved audience members are given headphones and masterfully instructed around the set, getting into the spirit of the event with bashful abandon. The complex tech work is flawless throughout and reveals just how well thought through the performance is.

The re-enactments are all filmed and projected onto a large screen. This is wheeled at intervals across the front of the stage and allows the image to be framed as it is in the original. Occasionally we break into a vignette that focuses more personally on one particular cast member. At these times the camera is able to crop in closer. It’s a decent shortcut to intimacy in such a large space. The individuals are peppered with would-you-rather questions, a relatively simple device that proves incredibly revealing about both their character and human nature in general. “Obama or Putin?” “Obama’s cock or Putin’s cock?” “Stoned to death in Afghanistan or lethal injection in Texas after fifteen years on death row?” “Pressured into wearing a bikini or pressured into wearing a burkha?”

It is certainly not a show for everyone. The next stage of the experiment is often stutteringly explained, and banter between cast members has a stilted feel. This delivery kills the pace in long sections, and an unusually large handful of audience members walked out over the duration. But this is a show that’s been touring for two years, with no need for different lines each night. The thoughtful pauses before answering questions and the awkward improvised feel must be rehearsed, and the raw feeling to the material intended.

What we’re left with is a celebration of people. Not just some (extra)ordinary nobodies on the other side of the world, but those of us in the room this evening as well. An acknowledgement and appreciation for our preferences, from the global repercussion carrying to the mundane, and all those thoughts that make us ordinary. Even if our main choice tonight was to stay in our seats and watch. Western Society didn’t always have my rapt attention, but I won’t soon forget the joy I felt watching Lady Eating Cake and Granny Dancing in the final clip, and I realise what hindsight what an enormous amount of very clever work went into achieving that moment.

Western Society plays at the Purcell Room at Queen Elizabeth Hall until 30 August. More information and tickets are available from the Southbank Centre website. Photo by Southbank Centre.