Dark ambient music explores the experimental fringes of ambient music, often using ambient sounds to create an unsettling or even scary soundscape. Dark ambient is rhythmless or uses minimal beats, and may include atonal synthesized washes and sample-based noise effects.
One of the earliest examples of what could be considered dark ambient was Brian Eno’s Ambient 4: On Land. This is the darkest of Eno’s ambient works. It is largely electronic, but also includes treated acoustic sounds. The sounds are not easily recognizable – it’s difficult to know if you’re hearing an instrument, electronic sound, or treated recording. On Land is a collage of mysterious, even scary sounds, that create a sense that you’re in an alien landscape.
Richard D. James, better known as Aphex Twin, released a CD in 1994 called Selected Ambient Works, Volume 2, that includes many cuts that could be considered dark ambient music. The music bears the indelible influence of Eno’s On Land, but James charts new territory, too. His ambient pieces tend to be less murky, but just as dark and mysterious as Eno’s work on Ambient 4.
Steve Roach and Robert Rich explore dark ambient territory on some of their releases.