GX-1

The Electone was the result of research directed at creating lively, natural tones close to that of musical instruments rather than cold, electronic sound.
It can also be said to represent Yamaha's first step into synthesizer development, featuring tone generator that offered polyphony equivalent to that of 36 conventional synthesizers, using group controlled voltage that allowed temporal change of pitch, tone, and volume.
The GX-1 is also well known as the synthesizer of choice for Keith Emerson and Stevie Wonder, and was acclaimed as a "dream machine."