That’s not a theremin beatboxer Ryo Fujimoto is using to accompany his vocals, it’s a new motion control device called Leap Motion. From Fast Company:
along with the platform’s $10 Geco MIDI software–he’s developed a unique performance that combines beatboxing with his mouth and filters and synthesizers through the motions of his hands. With his left hand, he can lift, rotate, and slide three different synths. With his right hand, he gestures to induce flanger, delay, beat repeat, and more.
Watch him in action below: