TL;DR time:

This is from the "Esper Edition" soundtrack for Blade Runner which is this amazing labor of love, fan-made thing that's been floating around the internet for a few years. It's basically the official Vangelis soundtrack CD (which is massively incomplete) mixed with a ton of unreleased music and ambient sound work directly from the film itself and unofficial sources, most of it with the dialog removed/mixed out surprisingly well. Apart from a few tracks, it's remarkably good quality too, I recommend BR fans look around for a torrent or download somewhere; it's really worth the hunt. The "Blade Runner Trilogy" CD set a few years back filled in some of the gaps left in the official soundtrack release, but this "Esper Edition" thing still remains the most complete soundtrack out there really. It's easily one of the best examples of fan-made stuff actually being super-awesome rather than retardedly geeky.