Random arranger keyboard video for reference:
https://youtu.be/sIWjlYMf49M

You can see right hand obviously plays a melody with a pre-selected instrument patch. A style is pre-selected on the keyboard for the accompaniment (similar to how we audition and select styles in BB). The keyboard has a row of buttons to start/stop the accompaniment, to switch between A/B/C/D variations, to increase/decrease tempo, and there may also be special Intro/Outro variations (with predefined chords based on a key) and drum fills that can be triggered and well as rests.


To recreate a similar set of features, it could either be built somewhere into BB or perhaps as a standalone app.

Before live playing, the following settings could be adjusted:
* Tempo
* Select style (existing BB popup window)
* Mixer (solo/mute/select track/erase track - reuse from BB)
* Choose instrument (MIDI patch or an external plugin such as Komplete or Arturia V-Collection or Spitfire)
* Choose split point (which is the lowest note that will play a note instead of being recognized as a chord)


Prominent buttons in the interface which can be clicked and linked to computer keyboard shortcuts and also MIDI controller buttons (CC mapping)

Buttons and possible keyboard shortcuts:
* Tempo Up (A) / Down (Z) / Default Recommended Tempo for style (Q or A+Z together)
* Play/Pause (SPACE)
* Drum Fill (X)
* Variation A (1) / B (2) / C (3) / D (4), etc where applicable for multi-styles
* Bass vol increment (D) / decrement (C)
* Piano vol increment (F) / decrement (V)
* Drums vol increment (G) / decrement (B)
* Strings vol increment (H) / decrement (N)
* Guitar vol increment (J) / decrement (M)

Don't read into the keyboard shortcut letters too much, it's more about their relative positions next to each other (i.e. A + Z, D + C are like Up/Down buttons).


Perhaps before playing live, users must click a Generate button after selecting a new style. This could generate various temporary WAV files for each real track with every possible chord and variation. Percussive tracks would of course be easier/different. When playing live and you press G+C+E keys on the left side of your MIDI (musical) keyboard, the program would intelligently find the pre-generated section for each real track for the current variation where a C/G and play that instantly (at the next 16th of a bar, now possible with BB 2022).

Inspiration for other features/settings could come from analyzing Yamaha/Roland keyboards further. If this were a separate feature I'd honestly pay a one-time extra $40 or $50 for it.

If PG-Music wishes, I could mock up a simple UI design for it.