I just got done making some sweet dubstep on the toilet.
Seriously, Turdstep is a horrible trend. This abomination to music being present in Zombies would only keep me from playing the mode.
How about something classic? Like say, Ratt? or other 80s music. Or umm... Some of that sweet Nine Inch Nails-esque music! Good ole Trent is already doing the score for the game, so I think this game is MORE than covered musically.
Why on earth would you want turdstep soiling the good name of Trent Reznor?