On a small plaza in downtown Pittsburgh, surrounded by tall buildings, you can stop to listen to the clouds. The sound actually comes from an unusual kind of instrument called a Cloud Harp, which has been programmed to respond musically to clouds passing overhead.
Nicholas Reeves makes clouds sing.
The University of Quebec professor of architecture says the idea emerged from his study of the geometry of clouds. He began to look at clouds as numbers - in a mathematical sense and from this theory made computer drawings and virtual structures.
"It completely changed what is meant by organization and order. It is a complete new shift in our way to see the universe and the cosmos in which we live. And, I tried to use this new tool to create architecture. And at some point there is an age-old connection between architecture and music and [the concepts] just drifted towards music," he says.
In Pittsburgh where the Cloud Harp is currently on exhibit passersby are drawn to the box-like wooden structure, where they can either squeeze inside or listen from the sidewalk. The computer program that drives the harp translates cloud height, density, structure, and weather conditions into audio sequences. Nicolas Reeves says it works much like a CD player, but on a much larger scale.
"In a CD player you have this very small laser beam that is directed towards the CD. On the CD are small holes, which modulate the laser light, and these modulations are collected by a small lens and converted into music. In the Cloud Harp, instead of small laser beam, you have a big one. Its range is 800 meters, which is about 2,600 feet. Instead of a small lens, we have a telescope and the role of the CD is played by the cloud itself," he explains.
The Cloud Harp plays 24 hours a day, seven days a week in all conditions except cloudless days.
The program assigns different synthesized tones from computer-sampled piano, brass or woodwind to correspond with clouds of different shapes and at different altitudes. While the Cloud Harp can be orchestrated in many ways, Mr. Reeves says its musical output is as unpredictable as? well, the weather.
"In this way the atmosphere would become like a gigantic musical score and the cloud passing from height will trigger different instruments," he says. "The harp can be polyphonic. It can play up to 32 instruments at the same time. If different instruments overlap on a height range, that will be polyphonic. But I must say that the cloud harp in Pittsburgh has a much simpler sound than the one we did before."
"One of the settings that I installed in Pittsburgh was when the clouds get close to the ground, the tempo increases and you have [many] more notes and the rhythm is intense. If you have fog or deep rain, the cloud will play very loud. The higher the cloud, the slower the tempo and when we get maximum high, then you get only very high pitched notes playing very slowly and it gets very relaxing," he says.
When asked if he looks at clouds differently now, he replies, "Oh, yes, completely! The Cloud Harp project began in 1997 and from this time [on] the sky [has become] a complete landscape. I keep on [discovering] how this [or that] particular group of clouds would play."
You don't actually have to be in Pittsburgh to hear the results. You can listen live on the Internet at www.cloudharp.org. Nicolas Reeves suggests, though, that you first consult the weather in Pittsburgh, a link to which is conveniently listed on the site. The Cloud Harp continues daily through August before it is packed up and shipped off to play another sky.