now-you-can-actually-play-the-worlds-tiniest-violin-thanks-to-ai-and-radar.html#tk.rss_all

Google's Project Soli plays a key role in the magic. Soli is designed for what the project calls "virtual tools," in which a gesture mimics the familiar interaction with a physical tool. In this case, of course, the gesture is the rubbing of thumb and forefinger associated with playing a tiny violin. Another key piece of the World's Tiniest Violin is an open-source machine-learning tool called the Wekinator.