I had this discussion with a class the other day. It doesn’t answer your question really, but the Requiem for a Dream soundtrack is rather unsettling if you’ve seen the film.
Threnody to the Victims of Hiroshima
A warning to those who experience frisson or have high empathy experiences when listening to music - this is uncomfortable. There is a beauty to it, one that is drawn from the very dissonance and frenetic energy in it, but it’s a piece that is meant to make you grapple with discomfort.
Nick Cave - Tell Me What That Is from the Wind River soundtrack. It’s more sad and unsettling once you know the context and what happens in the film.
Let me prefix this by mentioning that I only have minimal experience with the genre.
I think Livre Troisième from Les chants du hasard could qualify as unsettling/disturbing. Also check out their newest album, which goes into a more black metal direction, if you are into that.
The other one that comes to mind is The Umbersun from Elend
