Other things I like about FM that I was just thinking about:
- It's super CPU efficient on modern hardware, so you can use as many instances as you like.
- You can use it to do reasonably convincing physical modeling of many real instruments (or at least the start of it)
- There is little phase smearing or analog noise.
- Even for percussive instruments, you can tune and shape harmonic boundaries so that your instruments gel in the mix.
- Building instruments through sine wave decomposition/recomposition encourages bandwidth efficient sound design and instrument arrangements. They sound sweet to the ear, and instead of using the full bandwidth of a sawtooth or square wave, you can use the first few partials (or a couple choice ones) to sketch out the idea of one without taking up all of the space the full thing would.
- (At least with FM8), The multipoint envelopes editor is as flexible as a DAWs automation curve editor. It uses a zoomable spline based UI that feels a little bit like using Illustrator's pen tool.
- (Matter of taste) It's really easy to get retro video game sounds, so composing with these instruments always triggers pleasant nostalgia for me, even if I'm not writing VGM. This is not a surprise.
- Yamaha's sibling OPL/OPN (YMxxxx) series is responsible for powering sound synthesis in the Sega Genesis, MSX, Sound Blaster and sound cards and arcade game systems of the 80s and 90s.
If I can make a synesthetic analogy to a physical material, it's a lot like silicone. You can make it lifelike, almost unsettlingly or cartoonishly so. It pairs well, and fittingly, with the 80s and the 90s.