98 Nicolas Collins
Chapter 25: Video Music/Music Video
You will need:
- A video camera or camcorder.
- A video monitor.
- Photocell controllable oscillators.
- A cheap, hackable CCD video camera circuit board (see text.)
- An audio amplifier.
Various ingenious software tools exist for translating pictorial data into sound:
Soundhack’s “Open Anything” turns any digital file into a sound file (i.e., a
spreadsheet to-hit-record converter), STEIM’s “Big Eye” and Max’s “Jitter” track
moving objects in a video image and extract MIDI or audio information. But
here are two simple hardware approaches to the same task that bypass the
computer.
“Cloud Music” Revisited
In the 1970s David Behrman and Bob Watts collaborated on “Cloud Music,” a
video music project that translated live images of clouds drifting across the sky
into electronic sound. Photocells glued to the screen of the video monitor
controlled the pitch of oscillators in response to the fluctuations in light level that
occurred as clouds passed in front of the camera. In 1999 I saw two young Czech
artists do a cheap and noisy variation on this piece with a camera pointed out the
window at a country road. Yasunao Tone taped photocells to a screen and
projected film for his “Molecular Music.”
Try it. Wire up a few photocell-controlled oscillators (Chapter 18.) Place the
sensitive side of a photocell against the screen of a video monitor and use a thin
strip of tape across the back to hold it in place; repeat for each photocell,
distributing them across the screen. Hook up a camera or play back a tape.
Action! Instant soundtrack! You can do this on a projection screen as well.
You can also use the photocell gating/panning/mixing circuits from Chapter 22
to adjust the loudness of oscillators or other audio signals (CD, tape, microphone,
etc.) in response to fluctuations in the image.
Frame Rate Music
Connect the analog video output of a camera to an amplifier and speaker -- that’s
right, video output to audio input. Pan the camera around the room as you
listen. You should hear a steady drone whose overtones fluctuate in response to
the image content and brightness. The fundamental pitch is a function of the
video frame rate (NTSC or PAL specific,) while the overtone balance directly
represents the image data, line by line. Nice if you like drones. Try aiming the