The PSR SX900 is GM/XG/etc compliant by design. By design, Montage is not.

In order to make Montage play these MIDI files, you would need to do some additional work. It's not an automatic process.

Playing on Montage will always be an approximation and there may be situations where editing the MIDI file would be necessary for the result to sound more accurate.

The bottom line is that Montage is not a tool for playing standard MIDI files. That is not a goal of the instrument.

If the MIDI file you are dealing with isn't proprietary, commercial, etc (if it can be considered public domain) then you could share it somewhere and the steps to get it to sound "right" could be detailed by someone. Maybe just find a link to a MIDI file that presents the same challenges and share that link.

The only "setting" that would help is first recalling the "Multi/GM" init Performance. Otherwise, there are additional hand editing steps. No single button or setting.

Here is a thread from a couple of years ago, that you may find helpful: although the protagonists are a GENOS (as the GM/XG device) and a MODX (as the pseudo-GM device), it will apply almost in full with your PSR SX900 and MONTAGE, respectively, fulfilling those roles.

https://yamahasynth.com/forum/replacing-voices-in-gm-files#reply-105951

Bad Mister's reply is thorough. Hard to add anything to it. 🙂

As Jason mentioned, too, the PSR XG architecture and voice assignments are very different from the Montage/MODX architecture. If you move ahead, you'll need to be familiar with both architectures in order to replace the XG-specific voices and SysEx with the Montage/MODX equivalent. Be ready to put in some effort!

When faced with a conversion like this, I sometimes strip everything out except notes and basic MIDI controller messages like pitch bend, modulation, etc. and do a complete re-mix.

One thing that is helpful -- both architectures share many of the same DSP effect types. I often steal effect type and effect parameters from Peter to give to Paul.

Good luck! -- pj

although the protagonists are a GENOS (as the GM/XG device) and a MODX (as the pseudo-GM device), it will apply almost in full with your PSR SX900 and MONTAGE, respectively, fulfilling those roles.

Montage M8X, M7, M6 - by any chance is that conversion work any easier in the new Montage models?

My naive guess would be NO after reading the thread you referenced where you said:

Because the GM soundset’s rules do not require that edits to the various Voices be stored on the product, but are instead ‘stored’ as CC, Sysex, NRPNs, etc data in a Setup Measure located at the top of the file,

Yamaha Support told me that the new models DO support MIDI 2.0 but the above quote gives me the impression that the issue could have nothing to do with the midi version.

Would you comment on what the new models CAN do via MIDI that the previous models can not? Not asking for a 'how to' just about areas worth exploring.

Discussed here is proper playback of standard midi files (SMFs) which is a different set of specifications than the underlying protocol.

https://www.midi.org/midi-articles/about-midi-part-4-midi-files

The Standard MIDI File format is different from native MIDI protocol, because the events are time-stamped for playback in the proper sequence.

Some quick background on GM/GS/XG (which the PSR has stated support for and Montage does not):

https://www.cybermidi.com/helpdesk/knowledgebase.php?article=47

Thanks for the replies! Really appreciate it! 😀 😀
I read the other thread Bad Mister referred to.
I am willing to put in the work. But I'm a beginner when it comes to this topic. I think I need start with an easy tutorial which teaches me the basics first.
The links Jason posted can help me with that.
I'm going to try to find a useful tutorial. I Also use Cubase.

Discussed here is proper playback of standard midi files (SMFs) which is a different set of specifications than the underlying protocol.

I understand that - but I don't follow whether your answer is YES or if it is NO to the question I asked Bad Mister to comment on?

Montage M8X, M7, M6 - by any chance is that conversion work any easier in the new Montage models?

Are you saying NO, the effort won't be easier on the new models?

My thought was that perhaps the new models might process that 'setup measure' info, or process it more thoroughly, than the old models.

Or that maybe the MIDI 2.0 support would allow OP to take stuff in that setup measure and move it into the following measures of the midi file.

I would say there's no change.

@Roy - those links were primarily to orient Andrew why discussion of MIDI 2.0 is not altogether related. Those links won't be practical for you and your tasks.

Given your experience, I would return to suggesting making available a MIDI file you want to translate for playback on Montage and have someone walk you through the steps using something tangible.