Film Trailer Analysis: The Crazies

http://www.youtube.com/watch?v=J7w9uWFIMBs
the start of this trailer is different to what the viewer may think this film is about, with a very clean, stereotypical American town, for example kids riding bikes; baseball games and people shopping. this may give the viewer a false sense of security and may not be prepared for what is happening. the music in the background also enhances the start. but as son as the man moves onto the baseball pitch with a shotgun, the calm music vanishes and is replaced with abnormal sounds which shatter this sense of security. again, there is a view of the town that looks almost perfect, but now the viewers know that there is something wrong in this town. this is shown again in the scene where another man is taken to the doctors because of his unresponsiveness, he begins to repeat phrases "she worries to much, I'm fine". from here on the conventions of horror begin to show, with the setting of the scenes then at night, the murderer uses a knife, the area that this film is set in becomes deserted, etc.
later on in this trailer a song "mad world" is included, which fits in with the film title. the song is a fairly calm song, yet the clips shown  (which are muted to enhance the song) are far from calm, almost a complete contrast to each other.  later on in this song unnerving sounds start to come through the song to enhance the tension.