''It looks like a giant boob," said the girl behind me as we queued for tickets outside the huge white bubble that sprang up overnight in east London's Victoria Park. Her partner snorted with laughter, undercutting the subdued tones of hushed reverence from the people around her, staring up at the massive structure as if it were yet another modern art installation that they were struggling to understand.
Externally, at least, the bubble does have a certain bosomy voluptuousness, but here the associations with Carry On films and dirty seaside postcards end. Designed by the German architect Hans Walter Muller, it is home to the French trapeze company Les Arts Sauts's extraordinary show Kayassine, the latest act of the recent, well-documented "circus renaissance" to incorporate ballet, flying trapeze and music.
The bubble, like the show, is ambitious and innovative. The audience watches from low-slung, deckchair-like seats as, 20 feet above them in the roof of Muller's awesome construction, trapeze artists throw themselves from a metal structure, accompanied by musicians and singers who hover alongside the performers. Fusing music, lighting and flying trapeze, Kayassine is a show of overwhelming beauty and humanity, the trapeze artists, unprotected by safety lunges, taking on an ethereal quality that leaves the audience below gasping at their audacity. It is as if they really have learnt how to fly, and we, the near-horizontal, grounded audience, can only look on and wonder at the otherworldly majesty of it.
It is also a deeply cerebral and interpretive show. Dressed in white, the flyers are like figures from Greek mythology, their chorus, the crimson-clad musicians who provide a musical commentary to the action. The story of Daedalus from Ovid's Metamorphoses is quoted in the programme, and much is made of the symbolic association between cords from which the trapeze artists fly and musical chords, which, as well as original material, include interpretation of written works such as Kodaly's Third Movement, a Judaeo-Christian song and Meredith Monk's Long Shadow. Because it is based around the flying trapeze, this is generically circus - but reinterpreted to give it a higher moral and theatrical purpose than the traditional, family-orientated entertainment that is normally associated with circus.
Although Les Arts Sauts are keen to stress that they have nothing against traditional circus, they do not label themselves as circus performers: instead they are "aerial artists", their show an "aerial ballet". This is nothing new. During the 1970s, "circus" became a dirty word, tarnished by images of suicidal clowns sobbing into their cheap popcorn and dejected lions housed in tatty canvas tents that had long since lost their sequinned glamour. The circus earned itself a reputation as the lowest form of grubby entertainment, so when Cirque du Soleil, now a name synonymous with bringing circus arts back into the public arena, first came to England in 1992, its show was called, significantly, Cirque Reinvente. It returned in 1996 with the fabulous Saltimbanco at the Royal Albert Hall, the guest list heaving with politicians, rock stars and royalty.
It is largely thanks to the success of Cirque du Soleil that there are now circus schools all over England, and that shrewd directors are using circus as a way of luring a younger audience back into the theatre, namely Michael Boyd's The Tempest and Adrian Noble's Pericles, which both incorporate circus skills into the plays. Cirque du Soleil precipitated a movement that has at last made circus fashionable, elevating it to the status of high art.
But to write off traditional circus as something flawed and shabby is to miss the point. Cutting edge and visionary as they may be, the inspiration of Les Arts Sauts and Cirque du Soleil is firmly rooted in traditional circus, and they are a part of the ongoing evolution of circus that dates back to the late 18th century, when Robert Astley opened an amphitheatre near Westminster Bridge to provide an arena for performance skills. Indeed, the rumblings of the circus renaissance started in England, but at a time when the English audience was too jaded by "old" circus to understand the relevance of it. It is pertinent that when the circus king Gerry Cottle, who has been on the road for the past 32 years, started a circus school in England in the 1970s, there was minimal public interest. One of his students, however, was Andrew Watson, now creative director of Cirque du Soleil's latest touring show in North America. Similarly, when Brian Dewhurst opened the avant-garde Circus Senso in London at the same time, critics were distinctly underwhelmed. In the audience, however, was Guy Laliberte, who went back to Montreal and formed Cirque du Soleil. Thus circus had to go abroad to be reinvented, returning to England in blazing glory with a fresh, more artistic, and therefore credible, image.
"The current international circus renaissance exemplifies one of England's great missed artistic adventures," says Stuart McGill, artistic director of the Playbox Theatre, and currently sitting on the board of Mamaloucos, whose production The Birds will be going on tour after it finishes its current run at the National Theatre. "Circus is part of our cultural heritage, but performers today are terrified of using the word circus due to the negative associations that linger around the word.
"Although the Arts Council has recently appointed a part-time circus officer, and there has been an encouraging increase in the amount of funding offered to performers, we are still seriously lagging behind France and North America, where it is considered a legitimate art form. We also have the highest VAT rates on ticket prices in Europe.
"Cirque du Soleil has had a fantastic influence on the rebranding of modern circus performance, but in a sense its theatricality derives from traditional circus. Billy Smart's circus in the 1950s exemplified much of the showmanship now associated with Cirque du Soleil: a grand show full of ornate floats, dancers in fabulous costumes and spectacular aerial ballet."
Although Kayassine is a progressive, very modern spectacle, within the show's ghostly beauty are found many traditional circus images: a sexy girl in a diaphanous skirt, floating around in the top of the tent, lithe men performing feats of daring on the trapeze, their considerable grace and skill lampooned by burlesque clowns who bring an edge of raw comedy to an otherwise serious and highbrow show.
Circus derives from the marketplace and is therefore one of the earliest forms of popular entertainment, a phrase that now resonates with lowbrow associations, the inevitable hangover of Big Brother, MTV and fluffy-haired television presenters. But the girl who saw the giant boob in the outline of Muller's tent did have a point: circus should be fun; it should not have to reinvent itself as something solemn and serious in order to be taken seriously.