"What you're asking goes against everything PG Music stands for"
Bob, with all respects, I believe you didn't grasp the idea offered. When you load a style to modern arranggers, it loads both MIDI and Audio data. You simply trigger sections that are audio loops to output, while MIDI counterpart is numerically sends data to sound engine
Physical arrangers are software based things in a physical "body" with tactile keys and buttons.
Have you tried things like Kontakt Session Guitar series? A similar idea to Real Tracks. Can be easily triggered / transposed with your weighted keys controller and variations assigned to your favorite buttons
It doesn't know what you will hit next, but
has algorythm in place for smooth / natural transitions."what is the main purpose of Biab, what is one of the biggest selling points? It gives you a different version of the arrangement every time you hit play!"
Well, yes and no.. when you assembling/composing. But that should not be viewed as a limiting or negative factor if one day it would adopt live arranger functions. Contrary, variation would allow for more creative uses. Like with all things in life (including styles) some are great and some are so so. Likely, some will not sound good in "arranger" mode, and would have to be adjusted.
"Impossible unless you set it up first which takes the live playing part off the table"
Sure. Do you use styles straight out of your arranger, or you modify them somewhat"?
Future Xtraexrta 500 arranger compatible styles pack, taylored for live playing comes to mind.
Bottom line, it's likely not a very easy task, but not impossible. If sucessful, BIAB could become a pioneer in the game as it has the needed content and knows a thing or two about smooth transitions. Surely this will bring completely different crowd of live players to PGmusic world. Not everyone has $5k to spend on modern physical arranger.
P.S. Peter Gannon confirmed quite a few things in the wishlist that are comming to 2024, but I don't believe live arranger function was among them, however, if I remember correctly, it was mentioned that direct read from disk was on the table. If it will come to 2024 and works well, that would be the key element for future live arranger if I understand concept well myself