New Scientist tells us the less you see, the more impact spooky music has:
Sure enough, volunteers rated the eerie-sounding music – laced with staccato strings, ominous trombones, and weird effects – as more emotional than the “elevator music”-like keyboard tunes.
Under the gaze of a functional-MRI scanner, horror film scores elicited significantly more amygdala activity in the brains of volunteers who kept their eyes shut, compared to when they kept eyes open. Participants’ brains responded no differently to the neutral music whether their eyes were closed or open.
I bet this would work with any kind of non-neutral music. Anything that matters. In the dark.