1. Positive characters generally use clear chord intervals such as major triads 2. For negative characters, discordant intervals such as major seven and minor seven are used to express the darkness and entanglement of the characters. 3. Movie songs in the film It plays the role of transition, carries the turning point, heightens the atmosphere, and increases the visual experience that the picture brings to the audience. Just imagine how boring, dim, and dull a movie without music is! You will know the role of movie songs in the film!