I study all of the manuals because I'm always in search of a better mousetrap. Not so much additional gimmicky features, but thoughtful programming that can reduce the real time workload, while preserving a degree of "live" play, i.e., not just playing melody over a recorded MIDI backing.

I play a lot of church music which is typically played on an organ with bass pedals. Since I never learned to play the pedals, frequent chord changes are required to get the proper bass note-- sometimes one chord change per beat. So I need to be able to do more with my two hands (and quickly!), to make up for not using my feet. I don't consider myself a skilled musician either, it's really just a hobby.

Being able to play major chords by pressing a single note; and minors, sevenths, major sevenths, dims with just two notes is a huge "force multiplier." It often obviates the need to relocate your whole hand to reach the third or fourth note, and awkward hand positions. Many slash chords can also be specified with just two notes. No "extras" are required; all of the keys pressed for these shortcuts are notes that you would have to play anyway, if you were playing the chord on a non-intelligent instrument. Furthermore, Roland does not penalize you for playing all of the notes, it just doesn't require you to play them. Roland's was (is?) the best system of this type, as you might expect since they were among the first to sell a "professional" auto-accompaniment keyboard in the early 1990s.

The Roland system is alive and well in the FP-E50 (see p36 of the reference manual.) The FP-E50's chord recognition, OS, and many of the style parameters seem to be carried over wholesale from the FP-50 and FP-80, which in turn borrowed from the contemporary BKs. On the other hand, the owners' manuals and feature sets of the E-X series seem to borrow from Yamaha PSRs, which I'm also familiar with. That's why I decry them as not "real" Rolands.

Well, whatever works…

But is there any Roland arranger left other than the FP that uses the old system?

Thing is, you’ve already got what I think was the high point of Roland’s arranger line. Everything else you look at from this point is a huge step back, even the FP unless you are a decent pianist (which you admit you’re not) because, while you can use the old system on it, you can’t load any of your older styles on it, or edit the styles it comes with. Other than a great piano sound and a great action (for a pianist), I’m hard pressed to think of anything the FP brings to the arranger user’s table…

I rather fear that Roland have decided that, to compensate for lost revenue by no longer offering even mid-line arrangers, they are going to go with that paywall and lack of editing, forcing users to buy their styles. That’s a hard pill to swallow when the DGX’s still allow a pretty full featured arranger along with a decent piano and action (which you don’t really want).

Maybe if full chords are out, try the Yamaha system. I rather think that’s the only forward path for how you play… but with a BK9, I honestly think there’s zero chance of anything from Roland better, so why not just stick with that..?

Yes I still have my BK9, a BK7m and some older Rolands as well. I have a Tyros 5 too. For a while I set it up in my living room and gave it an honest try. The sounds, features, and display are great but I couldn't make my peace with their chord recognition system. If I wanted to leave two boards set up, I could MIDI the Roland into it. Otherwise if the BK9 dies, I'll be one of those guys out there playing a 20-year old module.
The FP-E50 is proof that Roland's Chord Intelligence "DNA" has been preserved. Someday they may again choose to offer a MOTL arranger, or tacitly license it to another manufacturer, as they did with the Hammond XE series back in the day. Meanwhile the FP-E50 is an heir, while I can only regard the E-X series as jesters and pretenders to the throne!

[Edit] I should also mention... last year I worked extensively with a gentleman from Hamburg, Germany named Klaus who was developing a software arranger called Nimbu. I *think* I convinced him of the merits of Roland's chord intelligence and he promised to include it. He asked me to test several key combinations and provide feedback. I never checked to see if the software was released. But if so, that would be another possibility.

The FP-E50 is a strange beast. As you point out, Roland’s one finger chord recognition system made it to the final product. But Roland’s style editing (even basic mixing of Parts) is completely gone. Along with two of the four variations, four of the six fills, and most of the intros and outros. Thing is, the code for all this is mature, bombproof, and, quite honestly, highly needed. The thought of being stuck with an 90’s feature set on a 21st century arranger just sticks in my throat.

Why deliberately choose to remove standard features that have been on ALL mid-price and upwards arrangers for at least 30 years? It sure didn’t make it a ‘better’ product. It’s a strange decision on a product aimed squarely at the more professional player? You get an awesome piano, an awesome action, and access to the Zen-Core expansion sounds…

And then, instead of just copy/pasting the arranger section from the BK9, you spend a fortune removing features that a pro player really needs. I don’t know about you, but the thought that I had to play every tune I do with two basic beats for the entire tune turns a promising product into a hard pass. I’d rather hook my BK-7m to a good stage piano with no arranger function whatsoever.

As usual, Roland get so close, then stumble at the finish line. Deja vu all over again!

Isn't it amazing the demand for the BK9 and BK7M remains high if you look at the prices when one rarely comes up for sale. Roland doesn't see this ? There is a market for higher end pieces

Compared to the demand for things like the current Roland synth lines, the arranger market is a rapidly diminishing drop in the ocean. We live in a tiny bubble, and demand for a discontinued product might seem high, but in truth it’s just a few hardcore users.

The fact that the few BK9’s that hit the used market are highly sought after simply reflects how poorly it sold during the production run, and how Roland never brought out a successor. And it seems like most who are looking at one at the moment are doing it more out of curiosity than an acknowledgment of how superior it is in many regards. You don’t really find that out until you use it.

And, as a pure ‘arranger’, it still fails to check off some of the boxes… Roland have stubbornly refused to add a break/fill or multipads despite decades of requests. You can use the Key Audio as a reasonable substitute for multipads for percussion and breakbeat loops, but its inability to chord follow cripples it compared to regular MIDI multipads.

If my entire show revolved around arranger play, I doubt I’d be using one. There’s been too much progress by other manufacturers to things like file linking chord sequences (and graphics files for sheet music) to registrations, multi-part chord sequences, audio clip launching, arpeggiators, samplers etc that the BK9 lacks.

For me, it hit the sweet spot if a great sounding keyboard with good sequencer and audio backing capabilities and an adequate arranger in a VERY lightweight and compact 76 without compromising the action. But I don’t think that, to a PA3X or Tyros hardcore arranger player it posed much of a challenge, and sales during its production run kind of bear it out.

Even to Roland users, it was an odd duck, being more a successor to the E60 than a progression from the G70/E80. Many didn’t want to take what initially felt like a big step backwards, and missed out on something that turned out to be a far more capable keyboard.

Yes, there are definitely all the pieces in place to make some fairly simple tweaks and feature fixes, and it would be a great arranger. But it appears that Roland have decided the market is simply no longer worth the effort. I wonder who’s next? Korg’s rather halfhearted, half-unfinished rollout of the PA5x with no accompanying mid-line models kind of echoes Roland’s bow out…