To be successful as a form of communication, Performance Art requires its presenters to deliver information with such conviction that the target audience, no matter how sceptical or disaffected, will be persuaded to the presenters' way of thinking. To be successful as an art form, Performance Art needs voyeurs.
For centuries, shouts of "Roll up! Roll up" heralded such events and drew nearby onlookers to share in them. Then, just before the dawn of the 20th Century, cinema came into being, so enabling far distant onlookers to experience far distant events.
In the first decade of the 21st Century, new channels of communication - Twitter, Facebook and YouTube - have made it possible, literally, to finger both performers and onlookers and persuade them to attend an event. This hands-on facility has made Performance Art the means by which anyone of us can deliver a powerful message to a target audience.
Fingers on phones drew attention to such events as T-Mobile's dance-gimmick, organized on Liverpool Street Station concourse in London. Copy-cat events soon followed, two of which were a seemingly impromptu performance by opera singers popping up in a Tel Aviv market and a similarly organized rendition of the Halleluiah Chorus in a shopping mall in Canada.
Nowadays, multiple happenings are being flagged up on devices worldwide with suggestions that people party or purchase or rally to a cause.
As I was planning this article, Egyptian tweeters were rallying more and more like minded people to Tahrir Square, Cairo to take part in an attempt to rid themselves of their President and his entourage. Respondents were undoubtedly encouraged by the Tunisian people's success in December of ridding themselves of a seemingly all-powerful ruler.
Most works of Performance Art end up being site specific try-outs.
Unlikely to be repeated, lasting for an hour or so at most, there is rarely time for them to be honed to perfection. But - as professional negotiators know full well - if performance energy is unflinchingly focused over a long enough period on the audience it aims to convince - there is a high likelihood of success.
Nevertheless, even when you know that the audience you are about to address has a willingness to listen and is unlikely to be at all combative, it takes a lot of pluck to nerve yourself up to alter minds and attitudes through argumentation.
To deliver a message unremittingly at odds with the ideals of a dangerously skeptical audience whilst surrounded by Militia and with voyeurs by the million taking stock of your performance, requires extraordinary amounts of courage and tenacity.
Though they had the excellent Tunisian example to follow, initially the Egyptian Performance Art presenters cast about distractedly seemingly unable to determine a common way to set about obtaining their desired outcome. Inexperience threatened to defray their message, and for a while the whole event teetered on the brink of disaster.
Then one individual took it upon himself to step forward, pull everyone's focus sharply back to the outcome the art form had been created to obtain and set the performance back on track.
Suddenly, all those involved in this humungous undertaking gained a new sense of purpose. They stood firm, channelled their attention, intensified their focus and rammed their message home with such energy that they impelled the targeted audience to accept its full meaning, acknowledge its full implication and bow to its full consequence.
"It is by spending oneself that one becomes rich," wrote the indomitable French trouper Sarah Bernhardt.
By sparing no personal expense the Egyptian troupers in Tahrir Square delivered a piece of Performance Art so persuasive that it created a new world order.
Some small credit is due to those who looked on. But enormous credit is due to those tweeters in Tunisia whose example evoked so coherent and successful a copycat reaction.
