Please don't skip this video. It's a little long, but it's also the key to understanding much of what follows:
Although Vanessa Beecroft may well be the most famous (and well-paid) performance artist, her work is all her own and not typical of much that may goes on in the avant-garde art galleries of Europe and the United States. Some of it is slow, elegant, to the point of being ethereal, such as the Butoh Dance Performance in Japan (below). I should also mention that the majority of such performance art involves human body movement and very often that body is nude or nearly so.
There is a nearly inextricable link between performance art and motion pictures (film or digital video) media. During the early days of performance art there was little or no effort to preserve the work of such artists. Today, the relatively low cost of doing so, and the possible returns to be had by the artists and their sponsors, usually entails turning such performances into media products for rental or resale. Oliver de Sagazan's Transfiguration (below) is about as far removed from Vanessa Beecroft as one could imagine. And though I would deem it is nothing short of "gross," my guess is that once you start watching it, as disgusting as it might seem, you'll be unable to stop the video.