An artist friend of mine is making a sculpture out of 12 gauge steel. It will be about 8 feet tall and 5 feet wide. He asked me how he could have it make sounds when people interact with it. I immediately thought of making it into a giant Theremin. It would be a simple Theremin with pitch control, but no volume control. If the dome is insulated from the ground, could the whole sculpture be the antenna? Can anyone recommend a simple circuit that I could build that would work with this? It should be able to be connected to a common audio amplifier and speakers.
It would be ideal if the whole sculpture could be an antenna, but if that wouldn't work, it might be possible for some part of the sculpture to be the antenna.
Is there another way to have the sculpture produce sound when people are near it? I don't think that an optical Theremin would work for this as the people would be interacting with it outdoors day and night in constantly changing lighting conditions.
When I googled to see if I could find any information on making a large Theremin, I found the giant Theremin in Melbourne, Australia, which isn't really a Theremin at all. That sculpture apparently uses video cameras and computers to detect people and produce sounds. That is much too complicated and expensive for this project.
Thank you for your ideas and assistance!