Tanztheater Wuppertal: Pina Bausch's Kontakthof, Barbican Theatre, London

A group of people take their chairs to the front of the stage, where they sit talking to the audience. A man passes along the line with a microphone, individual voices spring out of the babble. They're all describing romantic encounters: the horror of a date with spinach in his teeth, the excitement of a new partner, an embarrassing pet name. Many of the stories are funny. Most are cut off mid-sentence, individual experience becoming a chatter of human need.

Pina Bausch, who died last year, was one of the 20th-century's most influential choreographers. Her tanztheater, which uses speech and movement as much as dance, is a surreal depiction of often neurotic human behaviour. Her theatrical imagery is powerful, her shows often sprawling, aggressively long.

In memory of Bausch, the Barbican has presented two versions of her 1978 show, Kontakthof. They have the same steps, the same material, but one is danced by a cast of teenagers, the other by "ladies and gentlemen over 65". The run opened with the older cast – like the teenagers, drawn from the local people of Wuppertal, where Bausch's company is based.

Kontakthof means contact hall, a meeting place. Rolf Borzik's set suggests a dance or village hall, with panelled walls, a curtained platform, a piano and lines of chairs. The people could be meeting for a dance, though their behaviour soon gets weirder. The cast wear suits or evening dresses. The women's satin frocks, suggest the 1930s, like the old songs played as a soundtrack.

One by one, dancers come to the front, where they pose, turn, bare their teeth or hold their hands out, as if for inspection. Given that one of the women goes on to complain about bad or spinach-strewn teeth, the checkup may be needed. In pairs, they introduce each other, gesturing like magician's assistants, then hit or prod each other. Each small cruelty is applauded by the rest of the cast, waiting on their chairs.

A lot of the behaviour is childish: a man chasing a screaming woman with a toy mouse, playground bitching about other cast members. By casting older performers, Bausch stresses the undignified behaviour. Even as they throw tantrums, their age makes them seem more vulnerable.

Kontakthof mines traditional Bausch territory, but it's unusually funny. One dancer wheedles coins from the audience, because she wants to ride a mechanical horse. Bitchy remarks are sharply delivered. There are weighted dance scenes, the company striding into patterns or stopping to argue about them.

At three hours, though, this is a long show. Bausch often used repetition to emphasise how trapped her characters were, stuck in damaging patterns. The characters of Kontakthof are more free – they do actually have a good time, between bursts of cruelty and pain – but the pacing is heavy. Still, it's a distinctive work by an imposing 20th-century artist, performed with absolute commitment.