Matryoshka's are a big trend in Japan, being that they're toys. The Japanese versions are quite impressive like this theremin doll by Mandarin Electron.
played by Masami Takeuchi, master thereminist.
The theremin is an electronic musical instrument invented by Russian Léon Theremin in 1919. It's designed to be played without being touched (two metal antennas sense the position of the player's hands and control audio frequency from one hand and volume from the other-the electric signals are amplified by the speaker inside the doll).
