Yvonne Rainer, Trio Comment: watching this game for free sounds like a great opportunity | Art and design

ABehind Turbine Hall, three people are dancing. If it weren’t for the vinyl dancefloor and the white line separating the audience, however, you wouldn’t notice right away. You could be forgiven for thinking they were doing a Tai chi pose or, if this was a dance, that they had taken too much medicine: one rolls on the floor, another stretches his arms, a third sinks to his feet and touches his toes. They both seem so enthralled with their body movements that they ignore their colleagues on the stage and the audience in front of them.

This is to be Tate Modern On Friday afternoons, the audience includes not only art school children dressed like stage performers, but also babies screaming from the seats and misbehaving schoolchildren shouting loudly from the mezzanine. None of this seems to bother the dancers. After completing his routine, one leaves the mat and enters the door at the back of the hall. The others follow in their turn, and the audience applauds. After a short time, they are replaced on stage by three new singers, and the dancing resumes.

Yvonne RainerTrio A is one of the most powerful works that emerged from this extraordinary period in the history of New York culture from the mid-1950s to the mid-1970s. Tate’s play marks the 60th anniversary of its first rehearsal, when it was performed by Rainer (who continues to mentor new dancers in the field) together with David Gordon and Steve Paxton, and a moment of change in dance as an art form. The reasons for this are imprecise in explanation – it introduced everyday movements in art, dance separated from its traditional performances – but quietly enjoyed in viewing.

Each act lasts about five minutes and, if you join half way through, you can imagine that the dancers are moving well, so naturally everyone follows at the end. It may take a second look before you realize that the dancers are not only following a set routine, but that everyone is following it the same one choreography. It’s just that, doing this at their own pace, they soon lose sync. One of the things that makes Trio A so compelling to watch is that each player has the freedom to perform what they see at the tempo that feels most appropriate to them, meaning that some take longer or move faster for certain changes. There is no need to harmonize this rhythm, so idiosyncrasies appear in different versions of dancers of different ages and different bodies.

Rainer’s vision was to remove emotional drama from dance by insisting that the dancers ignore the audience and each other. So you get three people who are making the right advice to the benefit of no one but themselves. This dancer is weak, that the dancer has an image; his voice is clear, his is very clear. I’m reminded of 18th-century portraits that show the actor engrossed – playing the guitar, for example, or reading a book – rather than looking to meet the viewer. That we are defined by our inner lives and not by our appearance in the eyes of others is a modern day concept. Rainer extends this principle to dance. These dancers aren’t doing it for you, but that makes them compelling to watch.

What happens instead is magical, especially with the opportunity to watch over and over again what Tate chose to do as an exercise for several hours every day. Actions in choreography are equally divided: no form has more weight than any other, there is no idea of ​​tying the core or relaxing freely, there is success or disaster. In this respect, it reminds of other trance songs like Philip GlassAnother great artist to emerge from the New York scene of the time.

Just seeing well-trained people focus on fulfilling physical instructions, be they different in focus or beauty, feels like a privilege. That this should be freely available to anyone in London with a few minutes to spare, without having to pay the high entrance fees that elsewhere are turning museums into the leisure centers of the wealthy, is to be appreciated. For the two hours I was there, the audience was moving in and out as the dancers moved and changed. It feels right to the job that the dancers are allowed to go about their business alone, while the world revolves around them.