--Not so much interested in the idea of "soundtracks" as in capturing or creating impressions of various environments and settings. As certain sounds reflect natural landscapes and conditions, others evoke man-made topographies and urban "zones". Organic tones suggest the former areas, perhaps, while those associated with man-made instruments might subtly reflect the idea of human habitation.
All subjective-- nonetheless, I hear it that way, and so construct it. Cultural conditioning, evidently.
"Soundtrack" implies plot, character, action in progress. Let the listener instead have desirable conditions of any sort, any narrative or none at all (beyond the suggestive artifice of title and sound and imagery the artist offers).
What I would consider "Transformation Ambient" music tends to be unconfined, non-linear, insisting upon no particular mood, attitude, or temperament. It combines with the consciousness of the listener as opposed to demanding attention, moving through space and time, combinations and permutations, cycles and reflections, as opposed to the more "static" ambient forms.
