Frequency modulation
The Yamaha SHS-10 from the late 1980s has a small keyboard with 32 minikeys and a pitch-bend wheel, an internal Frequency modulation (usually referred to as FM) synthesizer offering 25 different voices with 6-note polyphony. Onboard voices include a range of keyboard instruments (pipe organ, piano, electric piano, etc.); strings (violin, guitar, double bass, etc.); and wind and brass (clarinet, flute, trumpet, etc.).