Is there any way to know what a MIDI recording is "supposed" to sound like?

MIDI of course is the music format where rather than explicitly give the data to reproduce a sound exactly, it gives a “score” that your player then plays. A near-universal format back in the days when bandwidth and file size limitations made it the format of choice for music. Which on the one hand means that you can tweak your settings to hear “The Star Spangled Banner” played on a harpsichord if you like; but on the other hand, if you have the same .MID file sound completely different on two different computers, how do you know what it’s “supposed” to sound like?

My dilemma stems from a twinge of nostalgia I had recently to rehear the score from the old Doom games. I found a site that let you play the MIDIs of the score- only it sounds way different from the music I used to die by. So was I hearing the wrong version all along, or do I need to adjust my current player? Has anyone rerecorded the “official” Doom score in .wav, mp3 or CD format?