What term is used to describe music that supports narrative or enhances the mood of a scene?

The term that best describes music that supports narrative or enhances the mood of a scene is background music. This type of music serves as an auditory backdrop that helps to set the emotional tone and atmosphere without drawing attention away from the dialogue or action taking place. Background music can subtly influence the audience's perception and engagement with the story, creating an immersive experience.

While ambient sound refers to the environmental sounds that are naturally present in a scene and sound effects are the additional audio elements that can enhance specific actions or events, neither captures the essence of music used specifically for mood and narrative support. Score music, although it often refers to the original music composed for a film, is typically synonymous with background music in practice, but it is not a general term as "background music" is. Therefore, the correct term for music that enhances the narrative or mood is indeed background music.