Incidental music is really an interrupted
film-score. Whereas in a film, the music
is very much part of the fabric, in plays, it
forms an interesting relationship with the
spoken and never takes over as such except
to aide a scene-change or an interval. At this
point though it has almost more importance than
the film-score because it 'stands alone' for a while
before disappearing altogether until the next moment ...from 'PASSPORT' . . .
when it will hide the shuffling of backstage feet or the
cranking of some machinery as well as keep the interest
of the audience... it can be more of a challenge to
write because of the natural limitations
of duration & scale