THE
SOFTWARE AND THE SOUNDS
WHICH SOFTWARE IS USED TO OPERATE THE HARP ?
Two different softwares have been written for the instrument.
The first one, called MIDI-LIDAR, based on the MIDI protocol, uses cloud data to modulate synthesized and sampled sounds ; when it runs, the sounds of familiar instruments, such as piano or strings, can be heard.
The second one, MINUIT-LIDAR, creates its own timbres and tones real-time, by using cloud data to shape the audio waves or to determine the harmonic structure of the sounds that are emitted. Over these sounds, samples of Quebec soundscapes are played. They include people telling tales, fiddlers, animal noises (whales, wolfes, birds, insects...), sounds of wind and water streams... From time to time, when the cloud crosses specific and very narrow altitude ranges, you may hear a human voice telling a French sentence, with an accent typical from Quebec northern areas.
Broadly speaking, the pitch of the notes is lower and the notes are longer when the clouds are low; high clouds create high pitch sounds and shorter notes. The density of the clouds determines the volume,
Though the Harp can be orchestrated in many different ways, no one can predict which kind of music will be produced. It can play melodies that sound quite musical, then switch to an electro-acoustic sequence. It can produce almost inaudible sounds, as well as rumbling ones.
Maintenance and development are done through the internet. During the Pittsburgh presentaion, new sound samples and new sound generators have been uploaded to the instrument from time to time.
WHAT WILL YOU HEAR ?
When the Harp plays, the laser beam that probes the cloud is needle-like: its diameter is about 30 meters at a 8000m (or 25 600 ft) height. This means that the reading is made on a very narrow spot, right over the Harp's highest tower.
If you hear a sonar-like sound, beeping at every 15 seconds precisely, it means that the sky is blue over the Harp, or that the clouds are to high and to thin to be detected (cirruses, for instance, are stratospheric : the Harp cannot see them). The sonar-beep means that the Harp probes the sky and waits for the clouds.
When clouds are detected, their height defines the frequency of the notes, and their density determines the amplitude of the sounds. Different instruments are associated with different altitude ranges. For instance,if you hear only short, grave sounds, slightly distorted, somewhat between a piano note and a bell, this means that low clouds (under 1100 m, or 3600 ft) are detected. Very short percussive sounds heard along with high-pitch sine waves correspond to clouds over 4800m, or 16000 ft.
Though this is not very frequent, you may hear sequences that seem to loop for many minutes : some cloudscapes have a strong regularity, which in some cases can be seen also by the eyes.
If you hear nothing while the Harp is supposed to be playing online (which it is not at the moment), well, something is not working... The Harp plays 24 hours a day, but this set of sophisticated systems and softwares can at times encounter unexpected problems (such as virus attacks, like the one that silented the instrument for many days on the beginning of May 2004). Though we monitor the instrument regularly from Montreal, we cannot check it every hour. If you suspect something, please send us an e-mail.
TO HEAR THE CLOUD HARP...
The Cloud Harp is not currently playing, but you can hear an exerpt from the 2004 presentations by clicking on the link below. This gives only a small idea of what tghe Harp can play, since it can produce an incredible variety of sounds, from rumbling ones to very delicate sequences, from almost classical to the most drastically experimental music, depending on the software that is used and on the "cloudist" who orchestrates the clouds.
This six-minutes exerpt illustrates the change between two different cloudscapes. On the beginning, a very high layer of rather thin clouds trigger long sine waves with a smooth envelope. Towards the middle, a lower cloud layer arrives ; the sounds change, they become much shorter and the music accelerates : the tempo is correlated with the cloud height, as well as the range of samples that are played. The sounds of this second half are processed human voices samples.
Note : regular computer sepakers are unable to properly render these sounds. They should be played on a good quality sound system.