Interactive art

SF Museum of Modern Art.
This was a fantastic toy : Walk into a large dark room. On one side 3 projectors throw the shadows of the people onto a huge screen.
Somehow, the screen is a radio wavelength dial, and the people are tuning the radio to different frequencies, and the sounds on that frequency are played into the room on speakers. The room is large enought for about 100 people, altho in fact there are only about 10 - 15 people there at a time.
Just wonderful watching people work out how it works - am I tuning into local radio, the police, a taxi firm, or a lunar explorer.

Outside, there were 3 computers linked up to about 20 small transistor radios and each computer linked to a mixing desk - one of those with lots of sliders that move up and down. I dont quite know how it worked, or what the significance of it was as art but is was great fun !