Hi,
You can serch the web and find a lot of .syx-files, there You find a lot of Voices/Performances which work fine.
Lot of that Voices or Performances are not great but some of whem are very useful an in the connection with programming effects and the Controls You get a very good resoult.
And it sounds far better as in the DX7.
Rainer

I think, the song's name is "What's love got to do".
Most, if not all the dx patches are already on the Montage. Certainly the e.p. and the famous harmonica patch.

You need a breath controller with the harmonica patch to make it sound anything like the original. You could use another continuous controller I suppose but it'll be tricky to get it to sound so expressive.

Shame the Montage doesn't have a breath controller input. Maybe get a 2nd hand DX7 and connect its MIDI out to the Montage.

But if you do that then you might as well use the patch on the DX7 😉

Or an MRTAudio type BC-to-MIDI device.

You need a breath controller with the harmonica patch to make it sound anything like the original. You could use another continuous controller I suppose but it'll be tricky to get it to sound so expressive.

If I read it correctly, the BC was use to control the volume of the patch. Honestly, I don't think that a BC is necessary to replicate the solo nor do I think that this level of authenticity is needed for a song. I would rather concentrate on applying the pitch(wheel) on the right time and level. One could use an expression pedal to control volume or expression but for that solo carrying the original dx7 with a BC just doesn't make sense.

On the original question of sounds and sources - Soundmondo.com is a place where you can get DX7 ROMs that are converted to Montage.

Some content:

VRC-102 ROM

The voice ROM cartridge "VRC-102" provides a large selection of musical instrument's sounds such as Flute, Oboe and Clarinet,e tc., from the woodwinds,Trumpet, Trombone and Horn, etc., from the Brass, furthermore Pan flute and Harmonica are available.
These voices are designed so that they are flexibly applicable to any type of music genre.

VRC-101 ROM

The voice ROM 101, belonging to the keyboard, plucked and tuned, percμssion group, is edited so that it can be used in different musical scenes, and provides many tones : those of keyboard instruments such as piano and cembalo, string instruments such as guitar and bass and tuned percussion instruments such as marimba and glockenspiel.

For a full list, see: https://soundmondo.yamahasynth.com/user/807

Then look at the bottom section "Sounds" and scroll down for the "MONTAGE" Keyboard Category.

Also note that the original DX7 ROM1 and ROM2 are available on USA.YAMAHA.COM (and other regional sites) which link to the FM Converter.

https://usa.yamaha.com/products/music_production/synthesizers/modx/apps.html

The very bottom of the page has downloads for the A & B groups for both ROM1 and ROM2 of the DX7. They are listed as "Trial data for Drag and Drop".

You can, certainly, find lots of SYX files floating out there on the net. The sources here are straight from Yamaha and either tested with the FM Converter or already pre-converted for Montage (and MODX).

Thanks all for your nice answers. Finally, I've downloaded the sysex files of the DX7. I have edited some of them I created my own version (the theoretical original ones were produced too).