A film score is original music written specifically to accompany a film. The score comprises a number of orchestral, instrumental, or choral pieces called cues, which are timed to begin and end at specific points during the film in order to enhance the dramatic narrative and the emotional impact of the scene in question. Scores are written by one or more composers, under the guidance of, or in collaboration with, the film's director or producer and are then usually performed by an ensemble of musicians – most often comprising an orchestra (most likely a symphony orchestra) or band, instrumental soloists, and choir or vocalists – known as playback singers and recorded by a sound engineer.