Dave,
Does the on board vocalizer on your Korg work independently of the rhythms engaged, as when you're playing guitar, or do the styles have to be playing? I've had to create a dummy registration with volume down work around to do this with the yamaha T2 I have. Effects will work without rhythms but not harmony.

Don/Donny,
Has this changed with newer Yamaha boards like psr970?

I may go back to outboard vh but wanted less wiring.