Not just a ‘theremin’ — that totally downplays the power of midi. Someone else mentioned the mimu gloves, and I love the idea of a vision based controller - almost everyone has a phone, tablet or laptop with a camera, especially if theyre making music.
I also love that this could blur the lines of music playing and dance.
Great job OP, thanks for sharing.
The Leap Motion Controller came out in 2014 already (11 years ago, wow!) and isn't very expensive. The SDK was lacking in the beginning if I recall correctly, but a webcam seems to be inferior. Technology isn't the limiting factor for a quite some time now. I'm sure many projects existed to translate gestures to MIDI, some less polished, some more polished[0][1].
Reminds me... I even used two PlayStation Eyes (EUR 5 each) with OpenCV and the EVM algorithm[2] on a ThinkPad X230 for a dance performance piece back in 2015. Movements rather than gestures and OSC instead of MIDI, but it worked great!
[0]: https://midipaw.com/
[1]: https://uwyn.com/geco/
[2]: https://people.csail.mit.edu/mrub/evm/