Okay, I did some work on this and Dekek A, thanks for posting the notes from the Manual.
For the
Style option, the left-hand background inherits the voices specified by the user's settings in the mixer. For the
Fixed option, they say, "via the specified Pad/Bass channels’ Voices, regardless of the selected Style." In the typical
unclear way Yamaha often expresses things, I believe they really mean that the background voices are set yo Yamaha's "default voices for the left-hand" sounds when the style is set to Off and the ACMP is still on. I don't see any method for altering those voices. To be fair, they're pretty generic and workable. So all things considered, I can make use of this feature for songs where I need to follow a singer ad-lib, and I have lots of them!!
Now the bad news !
Once again, we have another feature that would be so handy to set on most registrations BUT to make it work, we need to modify these registrations one at a time.......again!!! I'm sure Yamaha realizes the immense power of registrations. I don't see how anyone - including the very occasional home player - can get by without using them. So we have a monster called, "Registrations" but no way to control them. I was praying that Murray Best's program would have a feature where we could modify all Style Settings on our PC or Mac. An hour or two in front of the computer would probably do it. His program does a lot of things but not this. I was also hoping I could use a Freeze setting but that's a bust too.
So Yamaha, if you're reading this - we need an external registration editor for serious players!! I'd be happy to buy the darn thing!!!!!!!!!