Hi everyone !. I use an expression pedal on my KN6500 all the time. ( Some may say over use !) However I would caution against using one when laying down sequencer tracks. Adding "expression" in this way to a piece is something you should do to suit your mood at the time and I found it intensely irritating to have a backing track, even one that I had programmed going up and down without my control. Record your backing tracks without the pedal, then when playing, assign the parts that you want to control with the pedal to the "Part Expression" setting, not forgetting to switch the pedal itself to "Part Expression". Voila ! you can now control the backing parts volume with your foot whilst still using the touch sensitivity for the live lead parts.