It’s a theremin, which sounds like it should be one of the B vitamins, but instead it’s a spooky-sounding electronic instrument developed by a Russian scientist named Leon Theremin in 1920.
The instrument used two radio wave oscillators to generate the sounds, and musicians obtained its sliding sound by moving their hands along the theremin’s antennae.
Besides being found mostly on the sound track of horror movies, the theremin’s greatest hit was “Good Vibrations” by the Beach Boys.