did things using the spc700 tonight i've never heard done before, holy shit this chip is *weird*
spc700 fun part 1
spc700 fun part 2
and part 3 - there's more to this vid over on youtube, along with a download of the music in mp3+smc (rom files for emulator/console)+some SPCs.
tl;dr the spc700 is an up to 8-operator FM synth which happens to use samples as operators/oscillators. i had no clue how deep this and the echo buffer weirdness rabbit hole went, but it is impossibly deep.
i have, for years, heard people write off the pitch modulation function as not being anything too special. i now realize these people were not sound design geeks