Basically it's the song from the first 30 seconds of the following video. It doesn't appear to be on the released soundtrack and I'm wondering if the track has a name or has been released?

(Heads up, the video has spoilers from fairly early in the game onwards) https://www.youtube.com/watch?v=G-jkEDtQJMs

@trulyalive: If you want to avoid spoiling people you should really just link to the video instead of embedding it, the thumbnail kind of says it all.

http://www.amazon.com/Batman-Arkham-Knight-Original-Video/dp/B0101OS7XQ