 Later versions added an extra oscillator so that the Solo Melody section could be detuned from the rest of the synthesizer, resulting in a richer, "fatter" sound.The most effective use of the GR-500 may be found in the Polyensemble section, which, when combined with the infinite sustain system, made for a rich, symphonic sound.Also, the Polyensemble section, being basically a complex distortion circuit, did not require any pitch-to-voltage tracking, and so was not plagued by the pitch tracking errors common with early guitar synths.