Research- Use of Sound in One Film Opening

Purge

The Official Platinum Dunes Film, 'The Purge' film opening has a lot of chemistry within it to make it appealing to the audience.
It all begins straight away with a cctv footage of a murder scene going on, a man randomly shoots a victim, then there is infared footage of a knife crime going on, in the background there is quiet classic tunes heard throughout, while it gets to the end, it gets louder, as the crime worsens.