I'm not sure if this is what you're looking for, but it seems like Cubic Player may be what you want. I used to use it back in 95/96/97 to play midi files with the Gravis UltraSound soundfonts. The GUS was uncommon and expensive even back then. I seem to recall that Win95 wasn't too friendly with the GUS, so I never got one. I had an SB16+WaveBlaster instead and I used Cubic Player to hear what a GUS would have sounded like.
Yes, the GUS sounded much better than the SB16 and WaveBlaster. I still don't regret choosing the SB16 instead; it was way more compatible and had a much longer functional service life. I never had an A3D card either.
Anyway, it looks like somebody still preserves it here:
https://www.cubic.org/player/