for YM2612 + SN76489
by MetallicOrwell
Hello and welcome back. In addition to being a fun, quirky dungeon crawler, Mime for the PC-98 has one of my favorite soundtracks on the system. It was handled wholly by Hiroaki Sano (except for one jingle), and he sure was confident in his work, because there are three versions of it. Normally on the PC-98 you'd get OPN and OPNA versions, but in Mime you get OPN and MIDI, plus a CD that came (I believe) with some early releases of the game. As you'd expect, the complexity of the arrangements on the MIDI side of things is on a completely different level from what you get on regular-ass OPN, with its 3 FM and 3 PSG channels. For the most part, the CD sounds basically like playing the MIDIs on a high-quality soundfont--definitely a bit lusher than what you'd get if you owned a Roland SC-55 (which the game's instruction manual actually recommends) or something similar at the time. As for me, you'll be terribly surprised to learn I prefer the OPN version of the OST despite its simplicity. Yeah, didn't see that one coming from an FM synthesis fan, right?
I've covered Mime's music in the past, including Eagle Windeed (the main character's theme song) and most notably Wish, a surprisingly popular piece of music despite the game's obscurity. That one in particular was something I did early into my career (?) as a chiptune artist (late August of 2025), and so while it does still sound okay, I know I could make it into an absolute monster today, should I decide to have another go at it. Maybe one day, huh? This time, I've decided to cover another one of my favorite pieces from the game: the intro theme. It's called "My Dream", but it might as well have been titled "Overture in G Minor", because that's exactly what it is. I couldn't find any information on how the game's music was composed, but if I had to guess, I'd say the MIDI versions were made first, and then came the simplified OPN versions. When it comes to My Dream in particular, the first FM channel is for the main melody, the second one for detuned echoes, and the third for the bass. The three square waves are used for harmony, counterpoint, harp-like glissandi, etc. Pretty standard for the platform and time period, I'd think. The MIDI version has 16 channels, of course, and close to 20 notes playing at the same time in the busiest sections. It has piano, strings, horns, harps; all the orchestral stuff you'd expect.
Now, my intention here was to bridge the gap between the OPN and MIDI versions of My Dream, as well as to add some touches of my own. My weapon of choice is, as usual, the Sega Mega Drive, which is of course quite close to the YM2203 (OPN) in capabilities, but better. Its YM2612 chip has twice the amount of FM channels, basic stereo, and an LFO for vibrato and tremolo. It can also play PCM samples, but that doesn't interest us now, because I didn't use any samples here. The PSG part of the chip based on the AY-3-8910 was removed, and so instead we have the SN76489 as a separate chip (integrated into the VDP since the Master System days). It's more limited overall, but for a few extra square wave channels, it works well enough.
With all this in mind, you'd think that my version of My Dream would sound just a little lusher than the original OPN one, given the hardware is so similar, and yet the difference is considerable. The reason for this, the X factor if you will, is simply 30+ years of advancements in FM sound design. The internet and modern tools have enabled modern chiptune artists to iterate like crazy on what was done on these chips at the time they were commercially relevant. For example, I have every single FM instrument ever made for the Mega Drive back in the day in a folder on my hard drive. Think composers back then had the same kind of resources? I don't think so, dog. That's not even mentioning the wonder that is the Furnace Tracker, as well as the endless tools for all kinds of things imaginable that people post on GitHub. Also, because we are in contact with each other through the internet, you get the nerdiest motherfuckers from Russia, the USA, South America and so on sharing secrets and techniques on how to make your stuff sound incredible. That is why modern Mega Drive music is often on a completely different level from what was made for the console during its commercial run.
It's probably about time that the essay part of this write-up come to an end and I begin explaining how I made my cover, huh? I feel like it happens every time these days. So, why does it sound so much better? Because the FM instruments are better, that's why. The way I allocated my channels is actually pretty similar to what Hiroaki Sano did on the YM2203: there's melody, detuned echoes and bass, but now we also have two channels for chords. I used the sixth channel normally for the third note of the chord, but sometimes it's used for whatever's necessary instead, be it percussion, harmony or counterpoint. The SN76489's noise channel goes unused, while the three square waves do mostly the same things that they do in the original OPN version.
I based this on the MIDI version of the song, which you can extract from the game's files using some tools, but I still tried to bring it closer to the OPN version while making it better at the same time. What this means in practice is that I got most of the notes, tempo changes and so on from looking at the MIDI, but I ignored the instrument choices, favoring the original version instead. For example, if in one section there are high strings playing the main melody on the MIDI, but on the OPN it's done on a low horn, that's what we're going with. I used the YM2608 Tone Editor to extract some of the instruments from the .vgm file (again, amazing tools), but I often favored my own. My custom Orwell Strings see some heavy use, as well as the electric piano from YU-NO, modified Sakimoto brass and choirs, Molkirill's timpani and Zunpets... yeah, there quite a few FM instruments used here. I did like some of the stuff that Hiroaki Sano used on the OPN version, like the high piano, oboe, synth bass and so on, so I used those as well, albeit usually modified.
For a nice example of how I improved things: on the intro, I play the piano melody using the exact same piano instrument that Hiroaki Sano used, but the backing chords are played on the electric piano from YU-NO instead of the square waves, so they sound richer. I also added some choir backup with echo. Throughout the piece, I consistently use at least two notes for backing strings (the notes are taken from the MIDI version) and I also add some of the counterpoint and harmonies Hiroaki Sano included in the MIDI version, sometimes played on the square waves, sometimes on channel FM 6. There are some nice touches that are only found in the OPN version, so I used Maxim's Multidumper to, well, dump each channel onto a .wav file, so I could use Audacity's plot spectrum to inspect the soundwaves and make sure the notes were correct. When you combine all of this with the quality of the FM instruments, you get something truly special.
I am a huge fan of orchestral music done using FM synthesis and square waves, and My Dream is one of the best examples of that kind of thing that I've seen. Hiroaki Sano put a lot of effort into making an ambitious, massive piece for Mime's intro: it's over four minutes long, and it has all kinds of mood and tempo changes. In fact it's almost as good, if not better, than the best pieces from Brandish 3. I wish I had the vocabulary needed to describe and analyze orchestral music as well as I can analyze metal music, but alas, I'm still a novice musician. Regardless, I can say this piece gives me chills sometimes, in particular the section around the three minute mark with the descending chord progression. It's one of my favorite moments in any piece of video game music, ever.
Mime is not quite as obscure a videogame as it used to be (as evidenced by me putting this much effort into covering its music, for one thing). Also, it finally got an English translation in 2025, which is how I was able to play it. I think it's one of the best PC-98 games--a pretty fun dungeon crawler with a lot of personality and charm. You also bang prostitutes, which is to be expected given the platform. It's part of the magic of the PC-98: sleazy yet sometimes classy. If you haven't played Mime, I'd recommend you do so.
One last thought: I originally discovered this game because Saitama Saisyu Seiki did several arrangements of Wish. It all comes back to Senpai in the end, doesn't it?
See you around.
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