The difference between performance art and theatre is that the former create the conditions for something genuine to happen. It is something like framing the vital. Since Marina Abramovic’s commodification and the success of the biennial festival Performa, performance art has become more polished, packaged and museum ready. It is more a pose than a proper vehicle for life to emerge.

Howvever, at the Whitney Museum there is the opportunity to go to the beginnings of performance art in a wonderful archival exhibition called “Rituals of Rented Island: Object Theater, Loft Performance, and the New Psychodrama — Manhattan, 1970-1980”.

New York City in the early 1970s was a mess: bankrupt, or all but, and falling apart. One advantage to artists was the availability of cheap, empty space, notably in the Lower Manhattan industrial district that came to be called SoHo. Another was that, with the art market in the pits after the 1960s boom, there was a nothing-to-lose chance to experiment.

Onto the scene came artists who were as interested in language, theater, dance, music, social work, television, therapy and stand-up comedy as they were in painting. Performance could accommodate all of those interests. The medium wasn’t new; performance had flourished in New York in the 1960s, often as sensuous utopian countercultural events. In the 1970s, it grew darker, starker, brainier, more hermetic and more psychologically fraught.

The danger with this show in the context of a celebrity driven art world was to romanticise 1970s performance today as it is hard to recapture its original spirit and impact. Jay Sanders, Jay Sanders, the museum’s curator of performance, in consultation with the writer and film critic J. Hoberman — did a great job by injecting to the show a certain matter of fact tone that makes it believable.

The 20 or so artists in the show, almost half of them women, are an eclectic and uncategorizable lot, though three — Vito Acconci, 73; Yvonne Rainer, 78; and Jack Smith (1932-89) — can be counted pioneer figures.

In Acconci two personae (the performer and the human being) collapsed into one. He shadowed shadowed strangers in the street; for another, he aggressively crowded people in galleries. The work — which now exists only as a record, in grainy photographs — makes as much sense in our surveillance-soaked present as it did in the paranoid atmosphere of the crime-plagued New York of the early 1970s.

Rainer, a dancer, filmmaker, writer and a founder of Judson Dance Theater in the early 1960s, made personal narrative an essential component of her art. At the Whitney, her quasi-autobiographical, 1973 performance “this is the story of a woman who ….” is revisited in a collaboration with another artist, Babette Mangolte.

Mangolte, who filmed and photographed the original piece, has reconstituted it as an assemblage of her own images, with annotations and excerpts from Rainer’s script. Together, they give a sense of performance art’s potential for complex layering, and of its ability to leave elements that long defined value in modernist art — psychic truth, singular authorship — in doubt.

Performance, with its possibility for total immersion in muchness, was the only viable medium for someone like Smith, who lived art as much as made it. When Gladstone Gallery in Chelsea did a neat-and-clean Smith exhibition in its white cube space a few years back, the result was awful, deadly, murder by minimalism. The Whitney, at least, within limits, lets Smith have his maximalist way. It is that maximalist nonchalance and vibration that this show managed to encapsulate and that is not an easy task. Great!

“Rituals of Rented Island: Object Theater, Loft Performance, and the New Psychodrama — Manhattan, 1970-1980” runs through Feb. 2 at the Whitney Museum of American Art; 212-570-3600,