First, you have to tell the reader what you think are some specifically Dark, Ominous, and Foreboding pieces.In this thread you recommend to me your favorite Dark, Ominous, and Foreboding compositions. In other words works that you listen to when you want to wallow in your anger, depression, fear, or frustrations…. Don't lie we have all been there.
Please tell us why you find the suggested pieces to be categorized as such.
Hell, a lot of people's default setting is modern and contemporary classical, a lot as old as the 1920's - mid 20th century, because it is used so often as the 'unfamiliar' music under scenes of suspense and horror in films specifically because the general audiences are unaware of that repertoire, and the new and unfamiliar disorients, which is the desired effect to increase the viewers sensation of 'something strange or scary.' Within the film and video score milieu, that early 20th century musical vocabulary is routinely used, in often a highly derivative manner, to perpetuate that conditioning -- to the point where those scores, and all the music from which their vocabulary is lifted, has become a cliche sound for the emotions and states of mind you listed.
I don't use music to accompany or enhance 'mood,' either... i.e. it is neither medicine or therapy for me.
If this is for some study, I teethed on tuneful and gnarlier early 20th century music in my pre-school and kindergarten years, started piano at age six with Bartok: 99% of what most associate as 'creepy / scary, Dark Ominous, Foreboding, etc. is "Just music" to me.
Best of luck
and best regards.