Music for a Nonlinear Platform

I was very interested to learn how the dynamic music was produced for Rockstar's 'Red Dead Redemption.' For such a format where the player has so much control over the way the game is played, the music is successful in capturing the mood and immersing the player in to the game world. Instead of actually creating songs, the team produced stems, to be layered up according to the decisions that the player makes. In more linear platforms, as the player reaches a certain point in the game level, certain scores can be introduced following the pace of the action. Rockstar's very innovative approach allows the music to have this same effect, without the player being restricted within the open world. To get from point A to point B, one player might opt for a very scenic route, taking in the beautiful surroundings of the game world causing the music to be very minimal and lazy. Another player may choose to jump on a horse and race to next objective. In this case the stems would build up creating a very dramatic piece of music to accompany the fast pace of the gameplay. For this reason, with 'Red Dead Redemption' you really feel you are playing out your own unique experience. What Rockstar have achieved is a very open world style of gameplay with music that perhaps arguably exceeds that of a more linear cinematic platform.