I see the other forum some push-back if the instrument can even be represented at all on a keyboard. I don't agree with this push-back. Sure - it's hard to reproduce everything that an erhu can do. Same for just about any instrument. We're playing complex instruments with a different triggering/sustain/etc. system ("piano" keys) so there are compromises. Close enough for jazz is what we're after - not a replacement of the original instrument.

https://www.youtube.com/watch?v=S7H57ZpqVfU

Roland Jupiter (maybe others) has been including erhu in the standard set. The articulations shown here can be duplicated with Montage's AWM2 based XA.

This doesn't lead you to the set you're looking for - but demonstrates one way the instrument may sound and be controlled by "piano" keys.

There's an old thread that mentions erhu. One of the members promised follow-up which never happened. Maybe you can try. https://yamahasynth.com/ask-a-question/ethnic-library

... expect some of these libraries to have incompatibilities (hit and miss).

Close enough for jazz is what we're after - not a replacement of the original instrument.

Exactly! Close enough for jazz...

Roland Jupiter (maybe others) has been including erhu in the standard set. The articulations shown here can be duplicated with Montage's AWM2 based XA.

XA would definitely be key. I can see how the SuperKnob (or via a foot pedal) could be used for various expressiveness as well.

... expect some of these libraries to have incompatibilities (hit and miss).

Yeah, it may be difficult to find this in a library for the Montage (or via a Motif, etc.)

This is a programming challenge. Especially if there are no waveforms of an actual erhu!
If there are no erhu waveforms/library, then getting the base sounds(without bends or vibrato) may be possible using violin waveforms. My thinking is to find various erhu base sounds (soft, medium, louder/expressive) without any bend or vibrato, and capture them via a spectrum analyzer. Then use an EQ to shape the frequencing of a violin to be as close to the erhu as possible.

Then work on the expressiveness, maybe starting with the vibrato. Using the [Triangle +] wave type with the right speed and depth might work. Also, possibly change the timbre using resonance or an effect linked to the SuperKnob, the Mod Wheel or something. Can the Mod Wheel control more than one parameter?

Using a combination of XA buttons and various waveform elements at different velocities would give depth and expressiveness. As a starting point, a softer sound/lower volume could be used that has a slower attack, as an element in the lower velocity range, with Aftertouch set to increase the volume (& possibly the timbre or resonance...if it's even possible to have Aftertouch control multiple parameters).

Another element in a higher velocity range could have more attack of the bow sound to it.

Using either portamento, pitch bend, the ribbon, or a combination of them, while using Aftertouch for the volume, might emulate the slides closely, as well as the expressiveness in volume..!?

I am not familiar yet with motion sequencing & arps, but they may come in handy for some things as well.
It is definitely a programming challenge, but the best/most experienced programmer would likely be able to emulate much of this instrument & it's expressiveness quite closely.

Added Note: Both Pitch Bend and the Ribbon have that stepping sound to the bends, so they are currently not smooth enough to use for this unfortunately. Portamento is the only note bending that is smooth that I am aware of... If they fix the Pitch Bend and Ribbon stepping issue in the next update, then they would be useful for trying to emulate & synthesize this instrument.

Darryl,
You could download an appropriate Soundfont file from the net and then load it into the Melas Waveform Editor.
DSK have several free VST instrument sets available for download ie Ethnic sets World StringZ, Indian/Asian DreamZ.
There is the Asian DreamZ Soundfont from https://rekkerd.org/dsk-soundfonts/
When loaded into the Waveform Editor, the Erhu waveform has 6 Keybanks and there are also another 6 instruments in the collection as stated on the DSK website.
I have no idea how realistic the waveforms are to the real instrument, however it can be a work-around to your original request and also a freebie
I was thinking of loading the VST into Cubase however that is another story - being 32 Bit (Cubase 8.5) but are not recognised as they're SDK version 2.3.
Cubase requires v2.4 VST as a minimum.
Regards.

Darryl,
You could download an appropriate Soundfont file from the net and then load it into the Melas Waveform Editor.
DSK have several free VST instrument sets available for download ie Ethnic sets World StringZ, Indian/Asian DreamZ.

Thanks James, I'll check that out...

I wonder if the Montage could do the whole performance like this
https://www.youtube.com/watch?v=tu5XohUR3Pg

I wonder if the Montage could do the whole performance like this
https://www.youtube.com/watch?v=tu5XohUR3Pg

Yeah, I saw that one. I would use both that and this one when programming the Montage: https://www.youtube.com/watch?v=7fdFGEg-9R8

I think it would be very difficult to get it to that level to do an entire solo performance, especially without perfectly sampled & programmed erhu waveforms; however I think it could be programmed fairly closely using fiddles & violins(or possibly actual erhu samples) with the right EQ'ing, on multiple PARTs (using multiple Scenes potentially), using XA Assign1 & 2, pitch bend, mod wheel, aftertouch, (possibly the superknob/switch pedal), and various velocities...

It is a great programming challenge, but I may just take it on once I have free some time.