Curated by Harald Szeeman, this documenta show is still considered today to have been the most important ever, not least because of the shift in how art is presented. The conventional notion of art is no longer cogent for what is being produced: not only pictures, objects, and spaces are presented as art, but an artwork is now also a performance and a happening, or photographs and videos, circles of stones and discussion spaces. Very few visitors were prepared for what they encountered.