A live multimedia performance of music created using neural networks was premiered by the Irish Chamber Music Orchestra in Limerick last Thursday. The music, played to a backdrop of 1460 rainfall charts, corresponded to the raw data from which the composition, Bliain le Baisteach, was spun. An experimental Web broadcast of the event was also made.
The composition, devised by sculptor Sean Taylor and interactive multimedia design specialist Mikael Fernstrom, encompasses the rainfall for every day of 1999 and incorporates traditional Irish jigs, reels and polkas. Fernstrom used these melodies om to train neural networks to generate the synthetic version of Bliain.
It all started with Taylor's interest in the daily rainfall diagrams in The Irish Times. He wanted to do something artistic with the images and approached Fernstrom, the manager of the Interaction Design Centre at the University of Limerick, to discuss the possibilities. Fernstrom had spent some time researching sonic browsing - creating computer programs that would allow people to navigate through soundscape and screenscape simultaneously - so he knew the possibilities.
Working with a database of one thousand traditional Irish tunes, Fernstrom figured out that no tune needed more than 128 notes to describe it, and that no note was faster than 1/32 of a second. Using sophisticated mathematics and algorithms, not to mention a 600 MHz Pentium III computer with 512 RAM memory, he built two neural networks - one for pitch and one for duration - and fed them the tunes.
Then he reversed input and output and loaded the year's rainfall data, supplied by Met Eireann. He even managed to tie in tunes to particular weather stations, so that if Valentia had the highest rainfall on a particular day, a Kerry polka would predominate. What emerged was unusual, even for synthetic music - at times strident, at times melodic, distinctively modern throughout. Attentive listeners will find the references to traditional Irish tunes, which are deliberately buried deep in the composition.
Both the synthetic version and the one recorded by the ICO are on CD-ROM, which also carries images and may be obtained through the project website, www.softday.ie.
Anna Nolan can be contacted at anolan@iol.ie