There may be the following reasons.

1. Brainstem reflex: One or more basic acoustic characteristics of music are captured by the brainstem, and the brainstem recognizes this as some important or urgent information worth noting.

2. The "singing" of circadian rhythm and music rhythm: Some circadian rhythms (such as heart rhythm) of the human body are synchronized with music under the influence of external music rhythm/beat. People who have had live experience should have some experience with this.

3. Evaluative conditioning: Certain music always appears together with other positive or negative stimuli in a person's experience. The person will be aroused when hearing the corresponding music. Either positive or negative emotions (see: classical conditioning).

4. Emotional contagion: People feel the emotions conveyed by music and then internalize them (refer to: ***emotion).

5. Visual imagination: This is easy to understand. When you listen to music, you think of some visual images, which arouses the emotions associated with those visual images.

6. Episodic memory: Music reminds people of some of their past experiences and arouses emotions related to these experiences.

7. Expectations for music: During the progression of a piece of music, whether it meets or violates the listener's expectations for the music, it may cause emotions.