Merce Circus, Stratford Circus, London

Merce Cunningham, who died in 2009, was one of the great pioneers of 20th-century dance. This year's Dance Umbrella opens with a farewell to Cunningham, whose company will close after one last world tour – a final chance to see one of dance's great companies.

As well as more formal events at the Barbican, this last London season kicked off with Merce Circus, an interactive weekend at Stratford Circus. It was a mix of performance, study and 1960s happening, with events all over the building.

The centrepiece was a performance of the 1976 dance Squaregame. The stage was littered with duffel bags, which the dancers used as cushions or walls to hide behind. Sometimes the whole company plunged into activity, dashing about, breaking into trios and duets, milling back into a crowd.

A serene trio sent a wave of calm through the dance. Two men and one woman reached out and folded themselves up, shoulders undulating as their torsos swayed. Rashaun Mitchell danced a princely solo. He moved grandly through space, the carriage of his head and shoulders noble enough for any fairy tale ballet.

Mitchell came back for a wonderfully wobbly duet with Andrea Weber. They crouched to the floor and rose again, knees and ankles waggling. Cunningham was a mercurial choreographer, switching from elegance to vaudeville in a moment.

Weirdness is part of the Merce aesthetic. Dancers waddled with duffel bags held between their knees. At the very end, they grabbed the bags and rushed into a final group pose, as if ready to have their photograph taken.

After Squaregame, Merce Circus offered film screenings, a music concert and the chance to learn Cunningham's Field Dances. Created in 1963, it was inspired by the sight of children playing. It's a random dance, a group of steps to be performed according to chance patterns. A giggly bunch of school children, critics and dance fans went skipping through the steps.

It's simple enough to learn in a session, but the combinations are recognisably Cunningham. Set up to be as random as cloud patterns, they reflect his curiosity and invention, his distinctive view of life and people.

Merce Cunningham season at the Barbican runs until 8 October (0844 243 0757)