The “Hohner Multimonica” is a combined double-manual keyboard instrument consisting of a monophonic synthesizer (sawtooth oscillator, vacuum tube technology) and a polyphonic harmonium with fan-driven reeds. This electro-acoustic musical instrument comes from the German postwar era. It was produced in two main variants (“Multimonica I” later “Multimonica II”). The “Multimonica I” even had a built-in AM radio for local station reception. But there was also a version available without radio.