Douglas Irving Repetto is an artist and teacher. His work, including sculpture, installation, performance, recordings, and software is presented internationally. He is the founder of a number of art/community-oriented groups including dorkbot: people doing strange things with electricity, ArtBots: The Robot Talent Show, organism: making art with living systems, and the music-dsp mailing list and website. Douglas is Director of Research at the Columbia University Computer Music Center. Here are a selection of his own projects that I especially like.

Foal

‘Foal’ was developed when the organizers of Festival Rümlingen 2005 asked Douglas to exhibit his earlier piece ‘Horse Table‘. Instead he chose to build a new version of the table, this time in the form of an awkward foal, or baby horse table. The foal knows even less about the world than its parent, and spends most of its time blindly moving its legs every which way in a largely futile effort to explore the world.
See Video

Slowscan Soundwave

Slowscan Soundwave is a series of pieces that attempt to create simple physical manifestations of complex physical, biological, and social phenomena. Sound travels through open spaces via the compression and rarefaction (expansion) of air molecules. For example, as the head of a drum vibrates, it pushes and pulls at the air around it. That pushing and pulling creates areas of higher and lower air pressure, which propagate out from the source in waves.

Slowscan Soundwave 1 uses a microphone to sample the ambient air pressure in its environment. It then uses those samples to change the alignment of seventy nine suspended plastic sheets in an attempt to create a visible analog to those constantly changing pressure fronts. Even the simplest of sounds is too complex, and changes too quickly, to be accurately represented by plastic sheets slowly moving this way and that. As a result the patterns formed by Slowscan Soundwave are a crude approximation of those formed in the air.

Slowscan Soundwave 2 much larger version of the work consisting of ten giant suspended strips of transparent mylar. They overlap to form a radial pattern. Each strip is attached, via a string, to one of two small motors. As the sound changes the computer changes the speeds of the motors. One motor’s speed is tied to the volume of the sound in the space: as the volume rises, the speed of the motor increases. The other motor’s speed is tied to the frequencies present in the sound: as the predominant frequency rises, the speed of the motor increases. “Since the mylar strips are transparent and were hung about 60 feet above the audience, their effect was very subtle. At times it was difficult to even see them, while at others they would catch a bit of ambient light and then shimmer gently, causing water-like refractions and reflections. The effect was a bit like shouting into a pool of still water: subtle but definite reactions to changes in ambient air pressure.”

Slowscan Soundwave 3 was a further iteration made of five 15′ tall columns of transparent mylar strips hanging from the ceiling and two long swoops of mylar cutting a V across the room. continues exploring the idea of making difficult to perceive phenomena a little more perceivable, while attempting to preserve some of the the subtlety and beauty that make the phenomena compelling in the first place. Douglas explains, “Here I was thinking a lot about the way sounds travel, and in particular the idea that when a sound happens in one place it has repercussions throughout the space. So when a truck goes by the front window and makes a BANG! as it bounces over a pothole it not only changes the air pressure where human ears are listening, but also causes vibrations in the remote corners of the room. The zigzagging twine connections between motors and mylar, and the placement of the motors as far as possible from the mylar they’re vibrating, are attempts to get at these ideas. See Video

puff, bang, reverb

There is a grid of small wooden blocks hanging from the ceiling of the space. Each block is attached to the ceiling via a piece of monofilament (fishing line) and hangs about 6" above the floor. In the middle of the grid are two motors, each with a short length of wood attached to its shaft. Hanging in front of the grid at mouth height are two wooden panels. The panels are air-activated switches — when you blow on them they turn on the motors. When a motor spins it strikes the surrounding blocks of wood. Those blocks in turn strike their neighbors, which then strike their neighbors, and so on. The spinning motor acts like an impulse, injecting energy into the grid of wooden blocks. As the blocks knock into one another that energy slowly spreads throughout the grid.

This is roughly analogous to what happens when you blow, clap, or otherwise introduce a sudden burst of energy into the air. Your action displaces air molecules, causing them in turn to displace their neighboring molecules. This action reverberates though the air, transmitting the energy from your action to distant parts of the space. puff bang reverb is a semi-accurate, two-dimensional hyper-zoom into the secret life of displaced air molecules.