Graham......or others.....How is on board harmonizer on the Korg PA 800? That is of particular interest to me; especially after the awful disappoinment when I purchased my Tyros1 yrs ago expecting to use the built-in mike for harmony. Instead I have a rack mountable Digitech velcroed to my TryosKB. It sounds great, but potentially looking at a new instrument I do not want to be disappointed again if at all possible