I understand exactly where you're coming from but...it will play a #9, I just tested it and I've heard it many times but it does depend on the style. For the b9 use the slash bass like an Edim/C for the C7b9. That does work reasonably well.

Still, the vast majority of Biab users have no idea of what you're talking about. Monk, Dizz, Trane? Never heard of them. The reason the Real Tracks became so incredibly popular is most can't spell midi much less understand how to use it. And that's fine, they don't need to use it when the RT's sound awesome and are truly very easy to use. The RT's are the big deal now and like Pipeline said, to have the artists record all those extensions would really be difficult given studio time costs, file size restrictions and the like.

Consider this, it's not just the chord names themselves, it's the voicings. I don't have to tell you you can voice a b13 all kinds of ways on a piano. How is Biab supposed to handle that? The different voicings alone would require a RT player to record the same chord name 3 or 4 times on a guitar or keyboard. If it's a midi style, how do you weight that? Based on what? Use a different voicing every bar, every two bars or what? Randomize it? We already know how well that works. There's only so much you can ask a computer to do with high level jazz.

Those 7 chords (more with slash bass tricks) cover probably 95% of all popular music done in the last 50 years including Real Book standards like Ipanema, Misty, Embraceable You, etc. For the vast majority of users who care about those tunes Biab does a pretty good job. Yes, I'm well aware the Real Books are dumbed down, it's up to the players to do it right and I've written about that before. You're an educated jazzer and I get it but that's not the market PGM is going for.

Bebop has always had a limited audience even when it was current. Nobody was playing it at a private corporate function or a yacht club 50 years ago and certainly not now. And bars and pubs? Forget it. Here in SoCal, my jazz gigs started drying up 20 years ago and even then we were doing more funky fusion than bebop although we did some of it. Frankly it bores me because most players especially horn guys just play those transcribed Charlie Parker lines over and over and over...They're not really soloing.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.