The PSR-S500 used mega voices in the style so they may sound a bit more realistic (subjective) but the PSR-1500 offers more Fingering modes including an ON BASS that allows the playing of slash chords.
It(the PSR-1500) also has a modulation wheel, a recorder that allows 16 tracks(as opposed to nine) and the ability to hold more custom styles.
It also has an organ drawbar mode and better effects.
It is a far more pro instrument IMO.
Ian
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Cha d’dhùin doras nach d’fhosgail doras.
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.