Yes it's working, just playing around with it now. Trick is to do it in Realband you generate multiply vocal tracks, so I generated 4 separate vocal tracks and just copy the good bits from each track to a new track. Obviously the longer the usertrack and the more variations you have the better it will work.
EDIT:It works good, you have 3 different people singing because it changes the vocal key to match the chord, so you have a deep, mid and high, so you can have a single, duet or trio, Tim McGraw & Kenny Chesney.

Love_Again_mixdown.mp3