Laurie Anderson, Trisha Brown, Gordon Matta-Clark, Barbican Art Gallery, London

The full title of this show – Laurie Anderson, Trisha Brown, Gordon Matta-Clark: Pioneers of the Downtown Scene New York 1970s – does not rank among the pithiest of the decade. It makes this exhibition sound sprawly and messy. Which – like it or lump it – is what it is.

It is a show about three young artists who worked and socialised in the upcoming downtown district of New York in the early 1970s, that exquisite countercultural moment when the Soho district was coming into being as old warehouses were converted into loft spaces. Organised crime was being forced to decamp elsewhere. This is where these three artists lived and worked. Being young, they had an urge to do things differently. Object-making wasn't a priority, even of a minimal kind. They wanted their practice to involve the rhythms, the people and the despised stuff of the street, the often decrepit architecture by which they were surrounded. They disliked museums, all that cosseting and ossification of precious objects. They preferred art-making to be fluid, messy, provisional, and they wanted it to spill out of doors so that everyone would notice and feel they could play a part in it.

So this exhibition is as much a documentary of a historical moment as a presentation of things. There are lots of photographs and films here of what was done, and how people responded. Bemusedly. The drawings on show here are a frenzied and quite often unreadable means to an end; presentations of ideas, projects in the making (some of which never got made at all).

They all had slightly different preoccupations. Matta-Clark had been trained as an architect. He cut houses in half and showed bits of them as artworks. He was interested in despised or overlooked urban spaces, so he bought a long, narrow property that was wide enough to house a length of guttering. Then he photographed it, and joined all those photographs together. His collage-photographs of the interiors of condemned houses are some of the best things in the show, as delightfully maze-like and baffling as an Escher.

Brown was into performance – movement and dance – to be staged in unconventional spaces, and often by a mixture of professionals and amateurs. So we see photographs of a dancer walking down a street wall to the amazement of passers-by. Some of these performances are being re-staged at the Barbican. Performers in black climb a ladder, slip on a harness, and do their stuff. The walk looks as unremarkable as a casual stroll down a street – except that it's side on, and it's going on halfway up a white wall.

Laurie Anderson did unusual things with sound, so you'll find a pillow here that you are encouraged to lean your weary head on. It tells you a story about the childhood joys of going on the Ferris wheel and buying candy. She's a very accomplished cartoonist, too, and some of the lively, cartoon-style presentations of her wacky ideas are here too.

It's a pleasing show throughout, effervescing, stimulatingly ridiculous, full of the unrecoverable inanities of youthful idealism.

To 22 May (0845 120 7550)