I came across this video on Set Phasers to LOL last night. Plan 9 Pictures put music from Alfred Hitchcock's Vertigo with the opening scene from The Dark Knight. The way the dramatic beats in the scene match up with the music is a little freaky. The longer I watched, the more drawn in I was. I'm wondering how much Hitchcock's work influenced Christopher Nolan, even subconsciously, for the timing to be so close.
Another thought: This music also amps up the tension of the scene, I think, though I'm not sure if it's because it's this music or simply because it's different than the music I'm familiar with in the scene. I think the removal of all the dialogue adds to the tension, as well.