I do not own an XP, but I believe there is a "Performance" mode that you must be in......... you can then set up "zones" to play different sounds in different ranges....... I know this is how it is done on the XV-88 and I'm almost positive this is how it works on the XP-10/30. I would guess the XP-60/80 is the same thing.......

If indeed the XP-80 does have a "performance" mode, try going to it and looking for a "zone" button, make sure it is set to be "layer" and not "single". Then find where you can edit the patches that are played in the performance, it should be under some menu somewhere...... set up patch 1 to be piano and patch 2 to be strings. Then you can go back to "zone" and mess with the ranges and what-not. This all, of course, is dependent upon the XP-80 in fact having the same basic controls as the XP-30 and XV-88. Hope this helps somehow......

------------------
Romans 6:23 For the wages of sin is death, but the gift of God is eternal life through Jesus Christ our Lord.