Polyphony and monophony in instruments
Polyphony is a property of musical instruments that means that they can play multiple independent melody lines simultaneously. Instruments featuring polyphony are said to be polyphonic. Instruments that are not capable of polyphony are monophonic or paraphonic.
Typical monophonic synthesizer: Moog Minimoog
Typical duophonic synthesizer: ARP Odyssey
The Korg Monologue is a monophonic synthesizer with two oscillators and programmable note priority.
Each key on an acoustic piano is connected to its own hammer-and-string sound-producing mechanism.
The Minimoog is an analog synthesizer first manufactured by Moog Music between 1970 and 1981. Designed as a more affordable, portable version of the modular Moog synthesizer, it was the first synthesizer sold in retail stores. It was first popular with progressive rock and jazz musicians and found wide use in disco, pop, rock and electronic music.
Minimoog
An early 1970s Minimoog Model D synthesizer