Hmm ... I saw a detailed story background in a book when I was playing, and now I can't find that book. Let me repeat it for you. The first is the creation of the cathedral. One morning when barrios was walking in the street, he suddenly heard the beautiful flute, so he followed it to a church. This church is real, and the first movement describes the flute, so it is beautiful and soothing. The second movement tells about the magnificent decoration, the magnificent roof and the feelings he expressed when Ba entered the church, so this chapter is grand, solemn and sacred. The third movement is that after Ba came out of the church, he walked into the street. At this time, it was morning, and people came and went, forming a continuous and compact style of the third movement.