translation.en: It was invented around the 1920s, and the inventor, Léon Theremin -- he also was a musician besides an inventor -- he came up with the idea for making the theremin, I think, when he was working on some shortwave radios.
translation.zh: Léon Theremin在20世纪20年代发明了特雷门琴， 他既是音乐家也是发明家， 当他在研究短波收音机时， 他想到了制作特雷门琴，