In Hong Kong, there is an annual school music festival, involving various instruments and all musical students. They will compete in dozens of places at the same time. For several months, children with excellent results can get bonus points. points, becoming a springboard for entering prestigious schools. This competition has a history of decades in Hong Kong and has a profound impact on music education in Hong Kong.

In 2002, director Zhang Jingwei returned to Hong Kong from New York and listened to a large-scale music competition in Hong Kong, and began to want to make a documentary about the music festival. There were 13 children in a class who got good rankings that year. After Zhang Jingwei chatted with them, he selected 3 of them to start shooting, and the Huang family was one of them. He is the oldest among the three, almost 11 years old, another boy is 6 years old, and a girl is 10 years old. She is already quite famous in Hong Kong. Zhang Jingwei got an opportunity to go to the Czech Republic with KJ. The ticket originally belonged to Zhang Jingwei's teacher, but he had something to do and couldn't go, so he changed his name to Zhang Jingwei. So, there was the part in the film where KJ performed in the Czech Republic and was interviewed backstage.

After filming for a period of time, the director thought about whether to edit the film. The initial idea was to divide the stories of the three children equally, with each one taking one paragraph. But after thinking about it for a while, I felt that there was no good theme or hot spot, and there were other things at hand, so the enthusiasm and motivation waned, so the film was put aside. During these seven years, I still had contact with the interview subjects, such as attending their concerts and so on. Zhang Jingwei often meets KJ on some occasions, but does not take pictures of him specifically. However, the words he said backstage when he was 11 years old have always lingered in the director's heart, and the director was always looking for an opportunity to complete his story.

In November 2007, after filming "Song and Dance for Peace", Zhang Jingwei visited KJ at his home and found that he had not changed at all. Although his parents divorced and moved, and he grew up, his thinking issues and persistent pursuit of life have not changed at all. Comparing the two interviews, we found that the questions he asked were almost identical.

At that time, Zhang Jingwei decided to make this film, but because he also studied music, he was still worried that it would be too subjective. So I showed the information about KJ when he was 11 years old to director Ann Hui. In 2008, Zhang Jingwei started filming Huang Jiazheng again, and now the protagonist became him alone.

At the end of the film, Huang Jiazheng left Hong Kong and went to the United States. At that time, he had not completed his preparatory studies. The director felt that his life was about to start a new chapter, because Huang Jiazheng crossed Hong Kong and entered a new level, so the film ended here. At this point, the film, which took 6 years and cost 90,000 yuan, was completed.