Damask Rose, by Vangelis.
The first “Esper Edition” version of the Blade Runner soundtrack was a two-disc bootleg made by someone with access to the original masters of the music Vangelis recorded for the film; it restored over an hour of music absent from the official soundtrack, and can still be found now. This, though, I had missed - a five-disc effort from the same unknown individual, collecting together those two initial discs, music that only appeared on the workprint edition (with Harrison Ford’s awful voiceover), an ambient soundscape incorporating the sounds of the movie (there were thousands recorded in the studio), a bunch of remixes and a few tracks that Vangelis recorded which never made it into the film. It’s incredible. I have no idea how this exists.
I should add that linking to this is a copyright infringement too far for me, but you should definitely hunt this down.