Gleeman

Gleeman Instrument Co., based in Mountain View, California, was founded by brothers Al and Bob Gleeman. In 1982, they released the Pentaphonic, a rare five-voice polyphonic analog synthesizer featuring three DCOs per voice, a four-pole lowpass filter, dual ADSR envelopes, LFO, built-in chorusing, a 300-note sequencer, and an X/Y joystick for pitch and modulation control. Only around 30 standard Pentaphonics and 20 Pentaphonic Clear models with transparent plexiglass cases were produced, positioning it as one of the rarest consumer synths alongside competitors like the Prophet-5 and Oberheim 4-Voice.