I realize this isn't exactly the type of thing you find on HiFiCollector.com, but it's so cool that I had to share it. Ever heard of the Theremin? It's an electronic musical instrument that you play without making contact with it. Two antennae sense the position of the "players' hands and then interpret position into frequency oscillation (pitch) and amplitude (volume).
Wikipedia does a much better job explaining it than I do, so check out the entry HERE.
Here's a schematic it you want to build your own:
Ever try one? Seen one? Chime in and tell us your story.
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