Moog Concertmate MG-1 - Polyphonic Sound

Polyphonic Sound

The Polyphonic features of this synth are of particular interest as polyphony was rare in synthesizers of the time. The square wave based polyphony section is described as a "cheesy organ sound" by some, and well-used by others. Since the polyphony section is independently tunable, it can function as a rudimentary third oscillator, allowing the user to create more complex tones than on similar 2-oscillator synths. All of the sound-generating features come together in a mixer allowing the levels for the two monophonic tone sources, noise, bell tone and polyphony to be adjusted independently. The multiple notes of polyphony feed into the single filter, giving a Paraphonic result. In 1982-3, few electronic musical instruments had the MG-1 combination of paraphonic poly section and monophonic synthesizer in one instrument.

It is a common misconception that the Poly tones are not affected by the Contour settings. In reality the Poly tones can be affected by the Rise Time (attack) and Fall Time (decay) sliders. The Contour settings can only affect Polyphony while a key is pressed due to the Polyphonic gate design. When a key is released the polyphony tone for that key stops immediately. Therefore it is true that the Poly tones are not "faded out" by the Fall time (release) contour setting when a key is released. Similarly, the Poly tones are not "held" with the two VCOs when in "Continuous" (Hold or drone) mode. The rest of the modulation, including the sample-and-hold, will affect the Polyphonic Signal via the filter section. One thing to note however; the LFO cannot be used to modulate the pitch to create a vibrato of the Polyphony section. Against these limitations, the Polyphony is total, meaning all 32 keys can sound all at once.