The price of the most distressing piece of music goes to ...
Shostakovich!
Storytime: It happened in the beginning of February that I took the train back from Erlangen to my home city. At that time we just moved because of the end of our studies. I was not in the best of my moods (Corona, winter depression, missing closeness, a lot of changes, no job etc.) but the weather respected that at the day. It was the kind of gloominess in the morning you can see, with big clouds of fogs hanging over the landscape and brightness enough for contours but not much else. I brought an episode of the Listening Service with me. I never actively listened to Shostakovich but already heard his name in a different context. It was therefore time to look him up on Spotify. I listened a while to his string quartets and the second one in minor key was No.8 in C Minor.
The first piece is in tempo Largo and uses his signature motif DSCH (Dimitrie Schostakovich, like BACH) throughout. It starts like a fugue's exposition part where the motif sounds in each voice successively. The middle part introduces a very menacing/dark motif (like somebody is knocking) directly after restating the main motif and plays it along a happy tune. The third part tries to resume the happy tune but after a few notes continues to a creepy mixture of minor/major chords and the whole musical picture feels off from there on. The part ends with the knocking motif. (just repeating, found a much better analysis here)
During listening I got goosebumps all over and was probably in the perfect mood for it. Afterwards descriptions are like pure lethargy, subconscious threat, distressing, off-setting etc. but I can't really reproduce that feeling now. It is certain to say that Shostakovich was also not in his best mood ..
Supplement: I just found a Wikipedia article on the eighth quartet:
The piece was written shortly after Shostakovich reluctantly joined the Communist Party. According to the score, it is dedicated "to the victims of fascism and the war"; his son Maxim interprets this as a reference to the victims of all totalitarianism, while his daughter Galina says that he dedicated it to himself, and that the published dedication was imposed by the Russian authorities. Shostakovich's friend, Lev Lebedinsky, said that Shostakovich thought of the work as his epitaph and that he planned to commit suicide around this time. Peter J. Rabinowitz has also pointed to covert references to Richard Strauss's Metamorphosen in the Eighth Quartet.