“The computer game industry is a bit like the early days of opera: Composers are exploring untested ways of combining music, story, and visual spectacle. Fifty years ago, avant-gardists like Earle Brown and John Cage were leaving the ordering of musical events up to the players. Now this once-arcane technique is being used by game composers for far more commercial purposes. Composers call it ‘branching music’ — musical themes or tags linked to specific game events, designed so that any tag can lead un- jarringly to or from any other tag, creating a continuous flow, whatever the player’s choices.”