 The opening theme of the game features a neo-Gregorian chant, which was performed in studio by a 135-voice choir. Much of the underscore music that plays when the player is exploring the game, rather than during cinematic scenes, is based upon that opening scene. The composers made use of silence in many scenes, to build up tension for moments of a "pounce" effect, creating the effect with music that something is catching the listener. They deliberately saved the most intense music for the final chapter of Phantasmagoria, when the game becomes the most intense. During some chase scenes, drums and low strings are used in the score to simulate a heartbeat, which grows louder and louder during more dangerous moments.
