Play yourself out, Keyboard Cat. Theremin Cat is on the scene, showing effortless natural theremin skills on the solo from the Beach Boys' "Good Vibrations."
You can get a novice theremin to play around with for about $100.
The ones pros use, like the Burns B3 below, are about twice that and have a loop antenna that controls volume. This lets players pause between notes instead of doing a glissando between each note.
Here's YouTube theremin OG Thomas Grillo showing how it's done with a Burns B3:
