Does anyone know whether the music that plays during the decadent party at the beginning is part of the score or a pop song? Whatever the case, for me that's the most viscerally resonant part of the movie--the camera's slow move down the aisle of the bus, the distorted kick as it pulls up to the exploitative frat, and cross cutting this in-between programming the misogynistic website is a great irony worthy of the baptism/executions in The Godfather, if not quite subtle. For me that sequence is pure cinema, with no small help from the music.
That's part of the score. Reznor and Ross actually got to score as it was being cut, so they never ended up writing anything that wasn't used or had to be recycled because stuff was added back in (there's a reprise of the opening credits music but it has alterations and was clearly rewritten). That might also be my favorite part of the soundtrack, even above the Kubrickian take on Hall of the Mountain King.
I'm also thrilled that you have a Southern accent. It makes me less embarrassed of the one I've buried into a neutral whine (I guess that's what happens when you try to kill it, because Rosenbaum has a whine of his own to sound non-Southern).