Leon Theremin, also known as Lev Termen, demonstrates his musical instrument. (Credit: Wikimedia Commons)

Imagine a UFO descending from the heavens, its round disk pale against the night sky. What sound does it make? You’re likely imagining a keening whine in your head, like the howling of a haunted wind or the moans of a high-pitched ghost.

That’s the sound of the theremin, a musical instrument invented nearly a century ago. It was one of the first electronic musical instruments, and the