Heads he wins

You expect the unexpected if you live in the city. It's like a badge you wear. "I'm unshockable," it reads. Beggars on the tube, blood on the pavement, performance artists on the bus, shit in a phonebox. Nothing fazes you. A blank expression, a strong stomach, and you're away. And most of the time you are away, and as fast as your legs will carry you. Especially at night, off the tourist trails, in places where the electric lights don't shine. Which is why there's something heart-warming about finding a bunch of people - all kinds of people - shoulder to shoulder in the dark and pouring rain at the locked gates to one of London's oldest squares, trying to get a look at the mysterious goings on inside.

You expect the unexpected if you live in the city. It's like a badge you wear. "I'm unshockable," it reads. Beggars on the tube, blood on the pavement, performance artists on the bus, shit in a phonebox. Nothing fazes you. A blank expression, a strong stomach, and you're away. And most of the time you are away, and as fast as your legs will carry you. Especially at night, off the tourist trails, in places where the electric lights don't shine. Which is why there's something heart-warming about finding a bunch of people - all kinds of people - shoulder to shoulder in the dark and pouring rain at the locked gates to one of London's oldest squares, trying to get a look at the mysterious goings on inside.

By day these squares are tame - pretty leafy pockets packed out with sandwich-eaters and people feeding the birds. By night they lead an intriguing double life. Undergrowth is a cover for vice. If you've got any nous you won't go there, unless of course you're quite prepared - and longing - for what you'll find inside. But tonight is different. Tonight, in the middle of Soho Square, beneath the little half-timbered-cottage-style shed, there are shadowy figures at work. Strange noises fill the night air, and lights move among the rich canopy of trees. Out of the bushes comes a billowing ball of smoke, it drifts towards us and, as the gathered crowd watches open-mouthed, an old man's face appears, looming in the dark, filling the cloud. On the other side of the square, high on the wall of an office building, a giant hand is knocking. Knock knock knock, it goes. Knock knock. Dwarfing the windows, the hand strikes the wall. With the rest of the square hemming it in, the sound is sharp and clear. It's so loud, so real, that you imagine the building's inhabitants cowering in fear, hiding under their desks.

They needn't be afraid. There may be something out there, but it's not going to kill anyone. The hand is part of The Influence Machine, a new installation - opening on 1 November but given a trial run earlier this month - by American video artist Tony Oursler. Commissioned by Beck's and the influential London arts patron Artangel, it is the latest in a series of public art projects which have been held in the capital since 1992 and which include the seminal House by Rachel Whiteread and "HG" - a series of installations inspired by HG Wells in London's Clink Street Vaults, by Robert Wilson and Hans Peter Kuhn. It's Oursler's first public art project but you wouldn't know it to look at him. Shielded from the rain by a hefty chunk of stylish anorak, the 43-year-old has the appearance of a rock star preparing for a gig. This is not surprising - the New York artist has previously worked with pop artists including Beck, David Bowie and Sonic Youth and has always been involved with making music himself. Maybe it's this, or his clothes or the sun-dried texture of his hair, or the east-coast-meets-west accent, but he comes across as more laid-back surf dude than uptight New Yorker.

As Oursler and the Artangel crew work in the dark to finalise projection positions for the main event, it is clear that he is enjoying himself (though for the rest of us, the combination of electric cables and pouring rain lends a slight frisson to the proceedings). "This is something that couldn't really be achieved in a gallery," he says. "One of the great things about Artangel is that they try to do things that one could never do elsewhere." He seems delighted to hear that there is an uninvited audience at the gates. "It's kind of out of that ivory tower situation and that makes it dynamic for people," he says.

"Tony Oursler is one of the most visionary video artists working today," says Artangel co-director James Lingwood. Artangel artists are chosen, he explains, using a method of "informed intuition". "Tony has been at the forefront of exploring new technologies for over 20 years and his work is in a lot of galleries and institutions, but we thought it would work well in transforming an urban setting." It seems to be working. Everywhere you look there are projections. Disembodied voices fill the air. The projected heads are speaking: declaiming in weird tones. A woman's hair blends into the leaves of a tree. A strange thing happens: because of the rain, where the image touches the night sky you expect the colour to start running. It doesn't: if anything, it's clearer, polished by the rain. A line of red text cascades down the trunk of a tree. The giant fist is replaced by a video of Oursler, repeatedly stuffing his mouth with a piece of cloth and pulling it out. The whole atmosphere and the content of the work is deliberately spooky. There's a ghost theme here, and coming hot on the heels of Hallowe'en, the event will undoubtedly be read as something of a horror-fest. That's no bad thing of course - and for entertainment value it sure beats Gail Porter's arse on the House of Commons - but behind all the spectacle and jiggery-pokery, Oursler has some fascinating material and ideas to share.

Tony Oursler's work is complicated. When he talks about it he is slow and precise. Sometimes he starts sentences full of confidence then stops, checks himself, not, you feel, because he doesn't know how to finish them, more because he's not satisfied with them. Before he became successful - and that has only really happened in recent years - he worked variously as a teacher and a housepainter. These days he is single and lives alone in Manhattan. He has been working in video ever since he picked up a camera at California Institute of the Arts, where he studied alongside two other prominent US artists, Charles Ray and Mike Kelly, in the late 1970s. Oursler had been planning to paint - he'd grown up on the east coast in a small town called Nyack (the birthplace of Edward Hopper), just north of New York, and been taught by his great aunt - but he was instantly smitten with the then new technology. Unusually for a video artist, Oursler does not restrict himself to showing his work on a flat screen. His pieces - most recently seen here at his 1996 show at the Lisson Gallery - frequently involve a combination of projections, props and installations. Many feature dummies with heads animated by projected faces. Recently he has used blown glass devils' heads and lenses. "The two-dimensional situation for me somehow seems too traditional. I wanted to break that up a little bit and bring the work into a physical space," he says.

What strikes you, looking at Oursler's work - particularly in the light of the current me generation of British artists - is the almost total absence of ego. You may not be sure what you're looking at, but you can be certain it's not about him. Oursler agrees. "I've never understood the value of autobiography. I remember Laurie Anderson saying that she did autobiographical work until she caught up with her life, then she had to make things up."

Oursler makes things up, but there's always a basis in truth, a strain of research which gives it a resonance beyond the striking surface image. For The Influence Machine he put an ad in Backstage for actors to play the various characters in the projections. He mixed actors with friends and regular collaborators including Constance de Jong and Tracy Leipold. If you go to the show you'll meet characters like the teenage Fox sisters who in the 1840s in Hydesville, New York, started rapping messages to communicate with a character called Mr Splitfoot. You'll also meet Edward Gaspard Robertson and John Logie Baird - pioneers of the moving image in the 18th and 20th centuries respectively - and "The Technician" a character who, according to a contemporary US spiritualist community Oursler discovered, sends messages from the spirit side through televisions and the computers. Baird's inclusion is particularly apposite since his early experiments with television were conducted in his studio at 22 Frith Street, a stone's throw from Soho Square.

The Beck's/Artangel commission is the culmination of Oursler's painstaking research into what he calls the "deep history of media". In "I hate the dark. I love the light" - a kind of alternative history of light published in Introjection, a book which accompanies a retrospective of his work which is currently touring the US- Oursler demonstrates how the earliest experiments in moving image technology and communication were as much to do with entertainment as with science. According to Oursler, Arnaud de Villeneuve, a 13th-century showman and magician, used a camera obscura to stage a mixture of shadow play and cinema. "In other words there was a moving image installation in the 1200s that has never been taken into account by art historians. It's all seen as novelty but to me that's much more interesting than the fact that the camera obscura was used to help people draw perspective." It is no surprise that being able to play tricks with light and amaze and scare people went down especially well with showmen and charlatans - a fact acknowledged by Oursler in his cloth-spewing performance in The Influence Machine, referring to the fakery of spirit photography and ectoplasm.

The Influence Machine is named after a 1706 invention by Francis Hauksbee - a student of Isaac Newton - involving a spinning glass globe which threw off light and a crackling sound. But in a sense its title refers back to one of Oursler's earlier preoccupations with another luminous, crackling glass machine - the television. Get Oursler on that subject and he will talk at length about the wasted educational and artistic opportunities and lack of commercial controls that have tainted the output this 20th century invention. Nothing pleases him more than the rise of the Internet, which he sees as an opportunity to redress the balance. "It ends a 40 or 50 year reign of one-way communication," says Oursler, "and I'm very happy to see those guys go down in flames." He doesn't wish to come across as anti-television, but he suspects it of causing a numbing, of stunting human creativity, and his work explores the effects of the medium on people's psyches. He is, he says, interested in figuring out how things work, so that the dummy figures of recent years have been an attempt to understand the impact and sensations caused by watching and assimilating the multiple voices that populate our screens. He makes a connection between this century's fascination with the phenomenon of multiple-personality disorder - which he considers to have been a media construct - and our attempt to deal with and adapt to these conflicting voices.

All of this is fascinating, and a conversation with Oursler, or a look through Introjection, reveals that this is one artist who has a shocking amount to say. He is thirsty for knowledge; most of his visit to London was spent in London University's Harry Price Library - an extraordinary collection of journals, books and ephemera belonging to the 20th-century occultist - poring over a 17th-century treatise on optics and examples of spirit photography. The question, however, is how a live spectacle like The Influence Machine can possibly succeed in communicating all these ideas and all this information to an accidental public. Judging from the clamour at the gates at the test-run, countless people will stumble across the work in Soho Square and watch just for the hell of it. "The trouble with Tony's work," agrees Artangel's James Lingwood, "is that there's more to it than people realise. In the gallery the installations are so impressive in themselves that you don't always listen to what the figures are saying."

Oursler is aware of the difficulty: he's editing the scripts and projections to ensure that at least some of their meaning is spelt out emphatically. But Lingwood, whose imagination seems to have been caught by what he calls the "ghosts in the machine" theme, isn't worried: "I think it's fine if the content comes across in a fragmentary way - it's somehow appropriate. After all, spirits don't talk to you like professors." Neither do artists. In Oursler's case, we could do worse than to roll up and enjoy the work in which, in the best tradition of the moving image, all is not as it seems. *

Tony Oursler's "The Influence Machine" is at Madison Square Park in New York until 31 October and will be in Soho Square, London W1, from 1 to 12 November, Tuesday to Sunday, 6pm to 9pm.