Yes.

There is no separate GM engine in the Montage, like its predecessors (Motif-series, MOXF-series, S-series) it has the ability to respond to GM Bank Select and Program Change, but it does not strictly adhere to the GM spec. Short story, the file will select an appropriate Montage sound in place of the GM program change.

Files will not necessarily be "plug and play", you may need to edit the data to fit the file's data. Mileage will vary. Yamaha's theory on this is if you have a programmable synth you're probably interested in reVoicing the file and customizing it for your use, so the typical separate GM engine is not found... You get Montage sounds instead.

Without discussion about " why would you want to" do you know HOW to get the Montage into GM mode, SANS PC?

Yes, If I send a GM "mode on" from a PC - the Montage plays GM OK (I won’t comment further) but can't see how to locally do that (GM ON) without a PC?

It has GM "bank" (mentioned on pg 18 or OM) but other than the universal & standard SYSEX "GM MODE ON
F0H 7EH 7FH 09H 01H F7H" mentioned in the Data List PDF it was not discussed again.

That "GM Bank," upon some ferreting turns out to be 128 (plus GM drum kits) Performances (singles - aka GM patches/programs/ voices) spread out among its over 1900+ Performances. I don't have heart burn with that, actually be nice if next OS the USER could mark which piano, bass, EP, guitar, trumpet, etc was "tagged it" when GM was turned on!

EDIT
a Trivial Pursuit tidbit I guess, but looking at this some more it seems, unless I'm wrong, the 128 embedded "GM" Performances are: 1592 "Concert GrandPiano" to 1719 "Gunshot" inclusive.
EDIT

NO, I DID NOT buy a Montage 7 (had it for a few days now) for its GM capabilities or even to us as a primary GM module but it does come in handy from time to time.

Library Banks are almost as orphaned with respect to documentation about "How to" and "what about." I'm going to "play" with all the aspects of that one after posting including the "copy Performance from" mentioned in the PDF included with OS update 1.10.

Thanks

Thanks for the question, Larry.

Press [CATEGORY SEARCH]
Select INIT (it's one of the Categories)
Select MULTI/GM

You can view Parts 1-8
Hold [SHIFT] + [PERFORMANCE CONTROL] to view 9-16

You now have your GM Reset, sans computer.
If you send Bank Select MSB/LSB 000/000 and a Program Change from 1-128, you will select sounds in the normal GM List
If you send Bank Select MSB/LSB 127/000 a Program Change 1 you will select the GM Drum kit.

Thanks for info and yes that did it (trivial when you know how)

[BTW is "how to set GM performance/mode" (sans PC), or even a mention of term MULTI/GM, in some document, downloadable PDF, Yamaha Production Guide webpage or Essential Gide I'm missing? ]

Again
Thanks
Larry

Larry wrote:

Thanks for info and yes that did it (trivial when you know how)

[BTW is "how to set GM performance/mode" (sans PC), or even a mention of term MULTI/GM, in some document, downloadable PDF, Yamaha Production Guide webpage or Essential Gide I'm missing? ]

Again
Thanks
Larry

No, not that I am aware of... The INIT for MULTI/GM was a late addition.