That's like seeing the C13b9 as a modal chord of Db melodic minor. The same method can be used to relate just about any chord to any scale in my experience. Especially as you point out if you don't mind entering more than one chord to get the voicings you want.

What band in a box rarely gives you though is effective 'crunch' voicings involving more than one semitone in the voicing. So its hard to do a good Thelonious Monk pastiche IMO.

What's needed is a way of compiling a non-chord tone slash bass note like A7#9/Ab for example so that it pays in the piano part as well as the bass. This happens in Jammer Pro the 'other' accompaniment software which is still ahead of BIAB in terms of chord voicing and general midi tweaking of parts.

I've been campaigning for these features to be included in BIAB for years with no effect.
I think the reason is that BIAB's customer base has looked at Real Tracks as a one-stop solution for their accompaniment needs in genres which are less harmonically challenging in any case. This isn't a criticism just an observation.

Regards


Alan