A chord looper (Or as Roland called it a chord sequencer) has been available on Roland keyboards since the 2000s, Korg also added it, as well as the software arranger vArranger.
If you are using a computer there are 100s & 100s of VSTs on the market to get whatever sounds you want, and if you use vARranger or a Wersi OAX instrument they can load and use any VST you want.
Look at what's in modern arrangers (Or if you really want to go to town Workstations) and you can do pretty much anything you want.
BIAB is a fantastic program that has really evolved, and if you want to use it with a keyboard, just record the output as an audio file, load it into your keyboard (Most instruments can play audio files) and play along to it.
Anyway, thanks for posting, it's always interesting.
Bill
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English Riviera:
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