Here’s something for your need for an atmospheric ambient background track which has a mysterious feel to it. This dreamy track leaves much room for speech and would work well on documentaries or movies. The track also keeps the same mysterious feel for its whole 4 minute duration, so you can easily fade the music in our out if need be. Instrumentation includes low ambient synth sounds and reverberated and delayed piano.
You might also like my In My Dream ambient background track.