Listen to at least the first 30 seconds or so of this theremin and piano duet. If you’re not familiar with the theremin, it’s an electronic instrument played by placing a hand near each of its two antennas, one of which controls volume and the other pitch. There’s no physical contact involved during playing. Futuristic as it seems, it was invented nearly a century ago.
While the theremin — named for its inventor, Leon Theremin — is usually associated with spooky wailing heard in the soundtracks of Hitchcock’s Spellbound and the science fiction classic The Day the Earth Stood Still (but not, apparently, that of Forbidden Planet, which used ad-hoc electronic instruments), it’s suited to many other types of music as well, including classical and jazz, as heard in the clip above.
(According to the Wikipedia article, Lenin was so impressed with the instrument when its inventor demonstrated it to him that he began taking theramin lessons!)
When I was a lad in grade school (ca. 1957) we had a guy play one of these at an assembly. I believe he said he used it on the Captain Kangaroo show at times.