gloomy

moody

ambient

calm

dark

dreamy

murky

mysterious

chill

doubtful

down

dramatic

dreary

drift

drive

edgy

eerie

gritty

hypnotic

introspective

low

melancholic

mellow

muted

ominous

peaceful

pensive

purposeful

search

secret

shady

sinister

somber

spacey

strange

subdue

synthy

taut

tense

thoughtful

uncertain

underground

uneasy

waft

drum

synth pad

synth bass