The theremin instrument was invented by Léon Theremin in the 1920s, and plays spooky sounding notes based on a pair of antennas that sense the position of a person’s hand. Now — over 90 years later — YouTuber ‘bd594’ has created what he claims to be the world’s first Tesla coil version, providing greatly enhanced visual excitement, along with crackling arc sounds.
The device works by using a laser range finder to determine the note to be played, with the Tesla coil used kept electrically separate from the more sensitive electronics. The musical portion of the project uses an Arduino Nano for signal generation as well as a tiny OLED display for feedback, and features a standard MIDI output that allows it to be used with any compatible device.
With this setup, plus a metal mesh glove hooked up to ground, bd594 is able to align the laser sensor with his hand, while simultaneously catching lightning bolts that arc into it. Although the two parts could operate separately, it is a neat visual effect. He explains a little more about the sensor setup at the end of the video, showing how it can be used without the coil present. He elaborates further that it has a sensing distance in the 20-foot range or more, though sampling time increases as the target hand (or other object) moves further away.