I saw a Yamaha S90ES (I believe that was the model) at a session. What caught my attention was the 4 zone sliders the fellow was using to modulate strings, piano. Organ and another sound. I wondering if the XF can do the same and if so, would it need to be in performance mode or master mode?
Edit:
Issue of slider use answered after looking at manual. My apologies. I wanted to see if the XF sliders could be used similar to those in an S90ES I saw in use the other night. I've not used my XF "live" yet so my use of sliders in performance mode was nil. So I initialized a performance, assigned 4 different sounds to each part. To my chagrin, each parts volume was controlled by sliders 1-4. Nice to know if I ever gig out
The Master controller features in the Motif XF are double that of the S90 ES.
While in Performance mode both feature 4 Parts, so the behavior you saw would be exactly the same on the XF. In Performance mode you can control four Parts all on the same MIDI channel.
What you can do on the Motif XF is setup your favorite 8 Voices in Parts 1-8 of a Song Mixing or Pattern Mixing setup. Then you can associate that setup with a Master Program. You can turn Internal Zones ON and OFF using buttons 1-8, and external Zones with buttons 9-16.
Each can have its own slider. With this arrangement you can bring sounds in and out with the eight Control Sliders, making combinations as you require. Turn Zones On and Off using the MASTER > [Performance Control] feature.
Here is a tutorial on Master mode:
Understanding Master Mode Motif XF