The first sentence of the sleeve notes to the Irish Chamber Orchestra's collaborative CD Bliain le Baisteach (A Year with Rain) is wonderfully, er, dry: "Levels of rainfall and humidity in Ireland are high, especially on the more elevated locations in the West."

As if we didn't know. Perhaps the world over, no other word springs to mind so readily in association with this sodden isle as "rain". That notion had been marinating in the head of Corkborn artist and sculptor Sean Taylor, now working at the Limerick Institute of Technology. An artist who has always had a strong interest in nature and science, especially natural cycles, Taylor began to have a fascination with those little meteorological charts that appear daily in the back pages of The Irish Times.

At the start of 1999, he began to clip them from the paper and to think about the images and the representation of rainfall in mathematical form. The result - which merges the talents of University of Limerick interactive media lecturer Mikael Fernstrom and the Irish Chamber Orchestra - is a mixed-media, computer-generated but human-tempered composition.

Bliain le Baisteach was born out of rainfall data gathered by Met Eireann at 200 stations every day of the last year of the last century, meshed to a database of thousands of traditional Irish melodies, paired with a visual symphony of a full year of changing satellite images of the island being lashed by swirling.

"I feel there's mould growing on my shoulders, living in this country," jokes Taylor. He says the writing of Flann O'Brien - no stranger to mulling over the tendency of the island towards exceeding dampness - was a primary influence on the development of Bliain.

Once Taylor started thinking about all those meteorological pictures, "I found myself turning to those passages (in O'Brien's work) on rain again and again and thinking about it and the effect that rain has on our personality as a nation. I wanted to take it out of the morose and turn it into something positive," he says. A strong interest in music led him to contact Swedish-born Fernstrom, who has been with UL since 1995 and specialises in music and computing.

Met Eireann quickly agreed to supply whatever data was needed - which involved eventually condensing precipitation data from some 200 weather stations into information Fernstrom could use to feed into a computer. "I asked him, `how difficult is it to translate these numbers into music?"' says Taylor. Fernstrom replied that there was no difficulty, as long as they had enough data to work with.

"I've been living in the intersection between art and science since 1970," says Fernstrom, who is the course leader at UL on their media and technology degree programme. "This was the ultimate opportunity to do what we preach." He took a look at Met Eireann's data and noticed that it had the mathematical nature of fractals, which are a sort of organised representation of information that seems chaotic but actually have their own, inherent structure.

He then trained a "neural network" - a computerised way of interpreting and making sense of a range of statistical data - to associate each piece of data with a tiny piece of music, drawn from an enormous database of Irish traditional music. The database contained mostly polkas, jigs and reels.

"Mikael broke down the numbers and trained those numbers. The structure that a chamber orchestra uses to orchestrate a composition - Mikael broke those down into numbers as well, so the piece kind of structured itself," says Taylor.

Eventually, the computer turned the numbers into a composition which lasted seven minutes and represented rainfall on the island, beginning in January 1999 and concluding in December. Information from various parts of the country was mapped to sections of the orchestra - violins to Ulster, for example, and violas to Munster - to match the sequence in which an orchestra's instruments are generally highlighted in a composition with the sequence in which weather fronts coming in off the Atlantic strike the island: "It always hits Donegal first," says Fernstrom. "So you can hear the second violin hitting the coast first and then the spreading of the composition through the island."

For the Irish Chamber Orchestra, this was literally new territory, although they've done some electronically-produced music before. "As an orchestra, we're interested in innovative, new ideas," says orchestra chief executive John Kelly.

The computer-generated version, also included on the CD, lacked the texture of human performance, he says. "It was like opening a door and just a sound wall coming out at you. When the orchestra plays it, it brings in the human element."

"It turned out to be a very difficult piece of music to play, and demanded a lot of concentration," according to Kelly. Many of the challenges became apparent only when they went into recording.

"It would have been absolutely impossible for musicians to play the piece as it came from the computer," acknowledges Taylor. Some notes went beyond the capacity of individual instruments. Sometimes the speed at which notes were played exceeded human ability. "We had to take the raw, computer-generated piece and shape it," says Taylor. "You can't ignore the human touch - that's so important. The exciting thing for me was how the orchestra brought this thing to life."

The piece itself sounds like rainfall. It intensifies in winter, and grows "sunnier" in the spring and early summer: "To me, it's about the relationship between art and science and the ability to reduce everything to numbers, to digital information," Taylor says. The natural world, itself structured by precise mathematics, is measured by humans mathematically so that we can make sense of it. In Bliain, the "natural" world of rainfall and storm fronts is turned back into the mathematical structures that already underlie it and then channelled into audio form - another natural realm structured by mathematics.

Taylor is adamant that such melding of science and art demands no defence at all - either as art or as science: "I don't defend it at all. I'm not interested in defending it. It stands on its own," he says.

In the video sequence that accompanies the piece, viewers can watch an animated linkage of the four daily satellite images used by Met Eireann to track Irish weather, encompassing all of 1999: 1,460 images in all. Overlaid on the images are the names of the months, in Irish. "We put the months of the year so people could locate themselves," he says. "There's something beautiful about the names of the months in Irish and the links to pre-Christian times and events, like Lunasa."

The title of the piece, the men always knew, would be Bliain le Baisteach. The only alternative they considered was the very trendy "E-Flux" - "which sounded like a pile of old anal-retentive nonsense," Taylor laughs. "We didn't want to go down the pretentious art line with this. We also wanted to make it as accessible to everyone as possible." "

The project received strong support from the Arts Council and has been showcased at the Irish Pavilion as part of EXPO 2000 in Hanover, Germany. "I wanted to mark the last year of this millennium with this kind of project and with the language," Taylor says.

Bliain le Baisteach will be performed tomorrow night at the University of Limerick Concert Hall at 8 p.m., and will be broad- cast simultaneously on the web on www.softday.com.