Have you heard Russian matryoshkas singing? Japanese musicians have used them to create a new art and sound phenomenon. A special instrument is installed in each matryoshka to make them sing. The instrument is called the matryomin, and is the only instrument that is played with no direct contact.
The matryomin is a musical instrument that works like a one antenna theremin, integrated in a matryoshka. You can play a five octave range.Its name is the contraction of “Matryoshka” and “Theremin”.