Then there's a quick cut and the music starts with f minor. Softly but surely, the '80s song that was slowed down and made infamous through a montage of tears plays as people run through burning streets, as the military moves in, as people are strapped to gurneys, as they all fight to stay alive. Yes, it might be a "Mad World," but Gary Jules is not suited for it. In Donnie Darko, the song was beautiful, gut-wrenching, and perfect for the tone at hand.
Taking a cue from the song: I find it kinda funny that they decided to go with the recent hit rather than going back to the original. Why? It actually fits. The low, electronic notes that carry the Tears for Fears version are eerie, and if you watch this trailer for The Crazies over at Apple, and start the original song at roughly 1:40, it lines up. Suddenly the increasing chills of the beginning are made creepier. Even some of the action is perfectly synched.
The town fighting The Crazies might be a "Mad World," but there's no room for somber melancholia in a horror trailer -- especially when it's a song already made famous with a perfect cinematic fit.