Called "Orchestrating The Order: 1886.", the almost 7 minute long mini-documentary talks about the 'sound' they wanted their game to have. The developers looked to composer Jason Graves (Dead Space, Tomb Raider) to create the musical score that would further define The Order's tone.
Take a look at the video below. You'll hear from the developers, Jason Graves, and you get to see the orchestra playing and recording the music live at Abbey Road Studios.
The Order: 1886 is due for release on 20th February 2015 for PS4.