Have you played DOS version of Doom, Doom2 or Heretic back in the mid-90's on a computer with Adlib or Sound Blaster or compatible sound card? If yes, you should definitely remember the sound of these game's MIDI tracks played through the OPL2 or OPL3 chip and have some of the tracks or specific typical "instruments" written into your memory.
Nowadays, there still exist various Doom ports, which offer a built-in OPL Synth emulator, similar to the one inside Dosbox. With such bundled emulator, I can easily listen to Doom music in OPL Synth on a modern PC, playing Doom on high resolutions and many new features. The port I'm personally using is GZDoom - the best port for me, which offers really good quality OPL Synth emulation options - like several different OPL emulator cores. But what is most important, it even brings extra features, which were not available on real hardware (a real OPL2 or OPL3 chip): Full stereo panning (not only hard-left, hard-right), and Emulation of multiple OPL chips (up to 8 ), which brings much more available "voices" (72 voices in total for 8 emulated chips), so I'm basically unlimited in terms of amount of instruments and notes playing simultaneously, and practically any MIDI can be played back without dropping off notes.
Doom's OPL Synth "soundfont" (I mean each individual instrument's OPL chip register values) is stored in "GENMIDI" format. The soundfont was most probably created by Paul Radek, author of DMX sound library, which is used by Doom and which reads the GENMIDI file and plays back MIDIs through OPL chip. The GENMIDI format and DMX library is quite superior, compared to formats and libraries used by some different games of the era, especially because it supports "double-voice instruments". Which means, a single instrument utilizes two OPL chip voices (each one can have different parameters like ADSR, waveform etc) and additionally, the second voice can be detuned. Which gives much more options and possibilities to create more interesting, resonant and stronger sounds (no support for true OPL3 4-operator instruments, but still a big step forward).
The original Doom soundfont has many flaws, especially some instruments are bland or crappy, and do not really sound like how the instrument is supposed to. I noticed this after playing many different Doom maps and mappacks and listening many various MIDIs, so I got an idea to try tweaking those instruments and make them sound better. In the end, I came up with my own, significantly improved soundfont, which I called "Hisymak's GENMIDI" and I posted a thread about it here: https://www.doomworld.com/forum/topic/97388-u … -for-opl-synth/
In that thread, I made recordings of various Doom (and also other) music tracks, played with OPL Synth and Hisymak's GENMIDI soundfont. I think those were pretty cool...

Well, I did not stay only with Doom's MIDIs, and made something more.
While playing those various custom Doom levels, many creators used a MIDI version of a known real song in their levels. I could hear countless Rock/Metal songs in OPL, even Britney Spears's Toxic song in OPL, and much more like that.
That inspired me, well, to intentionally create an OPL remix of my personal favourite real song - for fun, challenge myself, and especially enjoy listening to my fav song in OPL. I chose a very good song from late 80's of my most favourite singer from my home country. I enjoyed creating this pretty much, as I love the sound of the oldschool Adlib/Sound blaster's OPL sound, as well as how I love this particular song. I hope you will like this too, or at least, find it somewhat interesting kind of musical "art".
I basically got the existing MIDI version, and tailored it to sound well along with the OPL instruments. I tweaked some of the instruments to go well with the song too.
If you have ever played Doom or Heretic with OPL (or an old PC with Adlib/Sound Blaster card), you will hear some familiar and beloved instruments, like the basses, the legendry harmonica-like sound from E2M8, Kevin Schilder's iconic Synth Strings that can be heard all around Heretic, and the deep Warm Pad which was screeching in the middle part of Heretic's E2M7 music.

This is the original song (for reference): https://youtu.be/CY2F_a5TW1U
This is my OPL remix: https://youtu.be/n4vE1X-DNNI
Enjoy and let me know what you think!