I'll start with the Glass Armonica, 'invented' by the one and only Ben Franklin (although apparently there were forerunners to Franklin, including Irishman Richard Pokrich), a curious instrument comprised of a number of glass bowls spun around and touched with dampened fingers to produce tones, akin to how sounds are made on the rim of a wine glass.
https://www.atlasobscura.com/articles/b ... s-armonica
Sounds of a Glass Armonica: https://www.youtube.com/watch?v=eEKlRUvk9zc

Okay, what are some of your favorite unusual/rare/unknown/eccentric music-making devices?