What on Earth is a "soundfont" in the context of actual music science? Can't you just put any audio through a bitrate limiter and put it in the right "soundfont?" What's the difference between the Mario 64 "soundfont" and the "soundfont," of any other game on the hardware?
A "soundfont" is kind of a collection of sounds stored in a .sf2 file Mario 64's soundfont is just every mario 64's sound they used for the soundtrack put in a .sf2 file To reply to your original question I HAVE ABSOLUTLY NO FUCKING IDEA they prolly used other sounds