There's also the matryomin: a single-antenna theremin inserted into a matryoshka doll. The Guinness world record for the largest theremin concert was set by a

There's also the matryomin: a single-antenna theremin inserted into a matryoshka doll. The Guinness world record for the largest theremin concert was set by a matryomin ensemble: https://www.youtube.com/watch?v=OnlsfeRNw1I https://www.youtube.com/watch?v=OnlsfeRNw1I