A psai Soundtrack consists of a collection of Themes. Just like themes in a film score, a psai Theme is a piece of music that will be played in a certain situation or a certain setting. In games we can't predict how long such a situation will persist, so the main difference to a film score is that a psai Theme is of variable length. While the game progresses, you may also want to adapt the intensity of the current Theme according to the current game situation. E.g. if the player is involved in a battle which is getting more and more dramatic, you may choose to raise the intensity of the music according to the damage the player has taken. To achieve both dynamic intensity and variable length, psai creates an interactive soundtrack by enqueueing short pieces of pre-composed music on-the-fly. These pieces of music are called Segments. A Theme always consists of one ore multiple Segments.