My fellow linguist and metalhead Sacha pointed me at these Youtubes of the late, great 80s thrash/prog/cybernoodle band Voivod. I actually hadn't ever heard their music before; I had only been assured that as a prog-rock and metal fan I would dig them. And indeed. Piggy is easily the most harmonically intriguing heavy-music guitarist this side of Vernon Reid and The Fripp. Some of this stuff is just plain out.
"Inner Combustion" + "Nothingface"