The dance music for Subject 3 is called "A Smiling River". Subject 3 dance became very popular on Douyin at the end of 2023 with "A Smile" and magical moves, and even became popular all over the world. Even the famous Latin dance master Joanna Loulis won the world rest dance The Grand Prix champion also danced subject three at the World DanceSports Competition. "A Smile in the Rivers and Lakes" is a song with the theme of rivers and lakes. It was written, composed, arranged and sung by Guo Zhonghao. The lyrics of this song describe all kinds of grudges and hatreds in the rivers and lakes, as well as a romantic depiction of swordsmen. The song's lyrics The melody is beautiful, the rhythm is bright, and the arrangement and orchestration are exquisite, making this song a classic martial arts song.