midi is kind of a digital score-sheet, not recorded audio, so the quality depends on the sound hardware you use for playing the tunes.
just because of that I still keep my SBLive in my desktop- it allows me to have a so called
soundfont file installed in the soundcards memory.
I did a websearch for the biggest i could fit in and load it,
then just start some classic adventure like Loom trough ScummVM and wath other peoples' jaws drop when they hear
that sound