I've never heard of such a thing. There are a lot of issues with that idea:
- The MT-32 instrument bank may not hold 128 instruments (the minimum needed for GM).
- The MT-32 can only use channels 2 through 9 (if I remember correctly) for melodic instruments and channel 10 for drums. GM needs at least 1 through 10, but many songs use 1 through 16.

It's important to realize that even though the MT-32 and GM synthesizers can speak the same language (MIDI), they really don't have anything else in common. If you have the patience, you may be able to get acceptable results by manually editing the General MIDI song you're trying to play on the MT-32 to use similar-sounding MT-32 instruments (either the default ones or sysex-programmed custom instruments).

Side note: Cakewalk is also able to send sysex banks, and you can also use it to embed them into MIDI files.

"MT-32 to General MIDI
This file contains a self-extracting archive that will rewrite the sounds of an MT-32 compatible device to the General MIDI sound arrangement. This file is compatible with the Roland MT-32, D-5, D-10, D-110, D-20, CM-32L, CM-64, LAPC-1 and other MT-32 compatible devices. This file also contains instructions in Microsoft Write format."

http://www.rolandus.com/support/genappstools/bin/MT2GM.exe

Interesting. Let me know how well it works 😀

it work's perfectly!! thanks!!

How good does it sound? I'll have to try it myself when I'm at home.

It's a simple 30sec long MIDI file that remaps the MT-32 sounds. Works well and sounds good. Be sure to play it through WMP or another MIDI player that handles embedded SysEx data. WinAMP doesn't, unfortunately.

Also, no amount of patching seems to make it possible to get the MT-32 to produce a decent piano sound, IMHO.

Lol.

Zum should have specified that he was looking for a way to play GM files on his MT-32, not the other way around... AFAIK, General MIDI doesn't support SysEx anyway. By the way, this GM SysEx for LA devices is very basic and is provided by Roland for "hobbyism purposes" only. There's no way you can come with a generic remapping SysEx that would be satisfying for every GM file available. At best, it sounds decent; most of the time it just doesn't cut it.

Oh, and for the record: SendSX.

That reminds me, you could probably use Midi-Ox and DOSBox to rip the sysex commands from later Sierra games that still support the MT-32 (e.g. Quest for Glory 3 maybe?). I've heard that they just map the MT-32 to something close to GM instead of using specially-optimized MT-32 music like their older games.

I'm trying it now... Pretty mixed results. Low brasses and synth sounds (of course) sound good, drums sound decent. Complex songs of course cause note clipping. Volume balance of some instruments seems off, with some instruments totally overpowering others. Drums are pretty good, but I think that MT-32 drums are mostly GM compatable already? Wind instruments sound slightly below average for a General MIDI synth. Strings are average.

As Kippesoep mentioned, the piano still sounds like a stringed instrument and not a piano, as is normal with the MT-32. I guess the MT-32 must have been invented in the days of Bach, when everyone was playing harpsichords (like pianos except they pluck the strings instead of hammering them) and the piano hadn't been invented yet 😉

I didn't notice any obvious missing tracks in the songs I tested, which is interesting considering the MT-32 doesn't normally seem to play anything sent to it on MIDI channel 1 (interestingly, one of the previous owners of my MT-32 sold it on eBay because he couldn't get a MIDI keyboard to work with it for this reason; I was able to get it working by using MIDI-OX and/or Cakewalk and mapping my keyboard's channel 1 output to one of the MT-32's channels 2 through 9 inputs)

Erm, you can make the MT-32 respond to channels 1..8 (instead of 2..9) by pressing "5" while holding down "master volume" and then pressing "1".

I obviously haven't read the manual...