Good questions Sufi ...
Right,
just to add to the general twilight, as already noted.
'Dark' ok - Sunno))) "It Took The Night To Believe", "Black One" as MMS notes.
Probably 'scary' for some pc's.
Rush Repuglicans should be made to hear this with headphones strapped on.
SPK's "Liechenschrei" (sp.?) was dark, borderline 'scary',
the Godflesh crew definitely have pulled more then their own weight in the struggle.
or 'Dark' as in 'dark ambient'.
Tim Hecker has some beautiful pieces in this territory on his latest, "Imaginary Country".
All taken with a 'different strokes' attitude as one's dark is another's light.
Sidestep genre police and dive in- plus there are probably more then a thread from previous dark music musings...