Lev Termen built this sometime between 1964 and 1967 while at the Moscow Conservatory, or, possibly, at the USSR Sound Recording Institute.
Theremin Center in Moscow, curated by Andrey Smirnov. It is in working condition.
This instrument was mentioned in the New York Times on April 26 1967 in an article by Harold Schonberg. Leon is quoted saying,
And here is my rhythmicon. It can produce any combination of complex rhythms. Let me play you seven against nine. Or would you like to hear 5 against 13? Very important. A conductor can stand here and learn to beat four with one hand and five with the other.
Lev continued to create instruments in Moscow and built this rhythmicon with limited resources, purely—it seems—for his own enjoyment and study.
Not currently available