Game audio must be integrated with game play in order to succeed as a soundtrack. For music this means embedding the music into the game rather than simply playing music on top of the game. We achieve this by designing a music playback system that includes opportunities for musical selection, mixing and music effects that can be controlled dynamically, and also by providing a logic system that can make control decisions based on game play. Thus we have a two layered approach to dynamic music - the logic layer, and the playback layer. In general the resultant music playing back must have the appropriate commercial appeal and "movie score-like" production quality aesthetic. This presentation will demonstrate both layers of the dynamic music system as well as choices made to achieve the final artistic goals.