A film score (also sometimes called background score, background music, film music or incidental music) is original music written specifically to accompany a film. The score forms part of the film's soundtrack, which also usually includes dialogue and sound effects, and 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 or band, instrumental soloists, and choir or vocalists – and recorded by a sound engineer.
Film scores encompass an enormous variety of styles of music, depending on the nature of the films they accompany. The majority of scores are orchestral works rooted in Western classical music, but many scores are also influenced by jazz, rock, pop, blues, new-age and ambient music, and a wide range of ethnic and world music styles. Since the 1950s, a growing number of scores have also included electronic elements as part of the score, and many scores written today feature a hybrid of orchestral and electronic instruments.
Since the invention of digital technology and audio sampling, many low-budget films have been able to rely on digital samples to imitate the sound of live instruments, and many scores are created and performed wholly by the composers themselves, by using sophisticated music composition software.
Songs are usually not considered part of the film's score, although songs do also form part of the film's soundtrack. Although some songs, especially in musicals, are based on thematic ideas from the score (or vice versa), scores usually do not have lyrics, except for when sung by choirs or soloists as part of a cue. Similarly, pop songs which are "needle dropped" into a specific scene in film for added emphasis are not considered part of the score, although occasionally the score's composer will write an original pop song based on their themes, such as James Horner's "My Heart Will Go On" from Titanic, written for Celine Dion.