Matters of life and death

Bill Viola's Nantes Triptych sounds formidable in outline. In reality, superbly installed in the Portview Trade Centre on the Newtownards Road, it is overwhelming. You climb several flights of concrete stairs in a functional, industrial building and enter a huge empty space. Three adjoining images, together something close to the format and scale of a cinemascope projection, make up a classical altarpiece triptych format. All of the imagery is confrontational and immediately involving, allowing you no distance. On the left a woman, attended by her partner, gives birth; in the centre, a man plunges into a pool and floats there, suspended; on the right, an elderly woman lives her last moments. Several people had anecdotal accounts of unfavourable reactions to all this. It was voyeuristic, sensationalist, unethical. The juxtaposition of birth and death was disturbing.

It is indeed disturbing, but also utterly compelling. The uncanny congruence between the new-born baby's crinkled expression, its aged look, and the dying woman's face is extraordinary, for example. It is also striking that Viola takes a medium renowned for its powers of artifice, even for its trivialisation of life and feeling, and drags it back into contact with the most basic horizons of our lives. I'd emphasise the "our", because the piece does address us on the most fundamental level, jogging us into an awareness of the parabola of our existence in time and space.

There is a piece in the Yoko Ono retrospective, Have you seen the horizon lately?, at the Ormeau Baths Gallery, that on one level aims at something similar. Vertical Memory imaginatively charts a woman's life in a series of identical, blurred photographs with captions succinctly recording her interactions with various male figures, from birth to death. Here, though, the subject is specifically the woman's experience of male authority figures. The work's gnomic understatement is typical of Ono. Overall it is a good exhibition that serves to underline the fact, if it still needs underlining, that Ono is more than John Lennon's widow. She had a significant avant garde artistic career in progress by the time she met him, and, despite their joint enterprises it is arguable that her own work was hindered rather than helped by her association with an icon of popular culture.

The whimsical humour, with strong, acknowledged overtones of Zen thought, which typifies virtually all of her conceptually oriented work, can be engaging when it doesn't overstay its welcome. Her Cleaning Piece, for example, is a good pun: a cloth and a clear perspex box on a base. And her half-a-room, a space occupied by half-pieces of furniture and objects, is striking. But the glass hammers and keys, the constant exhortations - to look at the sky, or pile up our troubles in a heap of stones, and so on - verge on the therapeutic glibness of self-help manuals: Yoko Ono's Little Book of Koans, perhaps.

A great deal of it is simply of its time, but then, ideas from the 1960s and 1970s are currently undergoing something of a revival among younger artists. There is a huge gap between early and more recent work (and the latter is not wholly convincing), but then presumably Ono had other things on her mind and was engaged elsewhere. Certainly, she has been a quietly influential figure, and not just in visual art - surely Bjork, for example, is partly inspired by her - and the show is intriguing. Also at the Ormeau, and on several advertising billboards throughout the city, David Byrne's photographs and photo-collages predictably relish garish incongruities, including the kind of Americana that featured in his film, True Stories. A lot of the images are from his highly praised photography book, Strange Ritual, but they are better in book form than isolated in groups on the wall. Byrne seems to really like sterile, manufactured environments. Under the heading Sleepless Nights, several sets of photographs arranged in grids record empty hallways and bathrooms, all with the bland, processed look of hotel decor. They are strikingly atmospheric. The billboards are very effective. Vitally, they look as good, as polished as the advertisements around them, but the quirky sentiments they express prompt you into doing a double take.

NOT under the banner of the festival but well worth seeing, Alfonso Monreal's show at Fenderesky, Whispering Processions, marks something of a departure. The works are fusions of oil, encaustic and silkscreen on aluminium. He uses a familiar range of soft, harmonious pastel colours, including pinks, greens, yellows and blues, but the surface is slicker than heretofore and his line is correspondingly freer. Apart from Byrne's billboards, there were two other big multiple venue projects: Catalyst Arts' Martin and Grassy Knoll's Resonate. Alas, the sheer logistics of getting around militated against seeing everything, and Resonate suffered most (despite the efforts of a particularly helpful taxi driver), but on a partial viewing it looked like a good example of the trend towards the tactful, pointed placement of art in public spaces.

Catalyst Arts's Martin is a stranger animal altogether. The title refers to George Romero's vampire film from 1978, about a young man who may or may not be a vampire. A number of artists were invited to respond to the issues raised. As mediated by David Goldenberg, Martin is an opportunity to present a critique of postmodernist and late modernist models of cultural practice.

The various segments of the show marshal a number of bids to confound conventional expectations. There is an air of disintegration about the whole enterprise that is wholly appropriate. The governing idea seems to be a version of the strategy, proposed by several critics of postmodernism, of constructing a "map of maps" as a means of attaining a viewpoint beyond the infinity of simulacra that otherwise engulf us at every turn. So, to take two examples, from Rod Dickenson we have meticulous documentation of crop circles and UFOs, and from Fiona Banner her personal "map" of a Vietnam movie, The Nam, informally recorded in exhaustive, mind-boggling detail, in print and commentary. With neat consistency, Catalyst then invites us to remake the exhibition as we would have it ourselves.

Most Belfast Festival events conclude on Friday, but David Byrne's Sleepless Nights and Yoko Ono's Have you seen the horizon lately? continue at the Ormeau Baths until December 12, and Resonate continues until December 5.