How to Spot a Psychopath

Yep, it's a cat playing a theremin (via).

[UPDATE: It's become a fad!]

This theremin has what sounds like a pretty nasty Stylophone sawtooth waveform, as opposed to the classic, more mellow, otherworldly-violin...

...but it's a theremin nonetheless.

Musical cats do not, of course, usually show any awareness that there's a connection between what they're doing and the noises that're being made. The cat walks down the piano because that's how you get to the windowsill; the cat plays the theremin because it enjoys bopping the interesting springy wire.

(Oo! Bill-Bailey-narrated theremin documentary {via}! See also the film documentary Theremin - An Electronic Odyssey.)