Most of the music within the play was to complete the scenery, in the sense that, most of the sounds were implying parts of the setting we could not see: the doorbell, birds chirping,  and things happening in other rooms.  Most of the music was also during setting changes, and it depended on the emotion of the scene, if the next scene was suspenseful, there would be suspenseful music.  Music was not a big part of the play, but it did help enhance the settings.