In Civilization III, as the game progresses, the music changes to reflect the era. There are five different mixes that represent the five major cultural groupings of the Civs in the game (European, North American, Middle Eastern, Greco-Roman, and Asian). During diplomatic negotiations with leaders of other civilizations, there are both aggressive and passive tracks for each culture grouping that play depending on the mood of the civilization the player negotiates with. All the music in the game is stored in MP3 format.