-he never asked for decent sound, merely softer, so of course the answer is Yes!
-Curt
Well, yes. Some music can be restored to a degree. I took it that "cold, cutting, caustic, harsh, metallic" was more literal, and serious degradation in sound can't really be fixed because the data just isn't there. Any restoration won't be an accurate representation of the original, though it can be less caustic on your ears.
I think "Die Eier Von Satan" by Tool would be a good test case to illustrate that as much of the sound is grating steel and the like.