The music name of subject three is "A Smile in the World".

1. The song "A Smile" has become a classic in the hearts of many people with its unique melody and lyrics, and its DJ version was even changed by the devil into the music of "Subject Three".

2. Excerpts from the lyrics of "A Smile in the Rivers and Lakes": When the rivers and lakes smile, the waves are surging, and the world of mortals is forgotten. What's the point of saying that everything is gone? The sky smiles and never grows old.

3. Subject 3 dance is an innovative dance form that originated from the combination of modern dance and folk dance. It draws on the characteristics and techniques of various folk dances and is choreographed through modern dance choreography techniques. , forming a dance form with unique charm.