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.
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. [....]
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.