Elec. instr. developed in Frankfurt in 1936 by Bruno Helberger and Peter Lertes. Similar to theremin, but with a guide kbd. and pedals to regulate vol. and tone‐quality. Range of nearly 6 octaves, capable of 4‐part harmony, and able to simulate human v. and some instrs. Played by pressure on 4 leather bands stretched across front, which sets up a current.