Scott,
I want to try to get something clear here. If what you want to do is set a split point on your keyboard and play three note chords on the left hand which will trigger a Drummer, Bass player, and up to 6 more rhythm tracks including guitars, keyboards, horns, etc., then the QY 70 will do all that.
If you want to play a chord on the left hand and play a single melody line on the right hand and have duet, trio, block, jazz, country harmony on the right hand, than the QY70 is not for you.
I can't tell if this is what you want. You mention "keyboard harmony's" in your post, and what that means to me is playing one note but hearing several as harmony voices.
Is this what you are looking for. If it is, there are no small battery operated units that will do this. The Korg i40m which is larger and has a disk drive, will give you harmony on the right hand while triggering chords on the left hand, or full pianist mode that will play chords accross the entire keyboard.
Please clarify this for me.
George kaye