To gain their support, Wu held a parents' meeting and let them hear the children sing. As she conducted, tears streamed down her face, and soon the parents were crying too. One father said, "I'll buy it. I can't bear to not support her. She loves music so much."

On performance day, the girls wore white dresses and the boys wore vests as they stepped onto the "city school" stage they had long imagined. They were nervous, but their eyes searched the audience for familiar faces — former teachers, classmates who had transferred — hoping to be seen. They sang a piece adapted from classical poetry: "Green Trees Cast Deep Shade and Summer Days Stretch Long."

Their parting, too, would come in summer. The day before she left, students wrote her cards: some said she was a beautiful teacher, some called her strict, and others energetic.

The final Kodaly class was held offline. Wu presented her final assignment — a complete performance video. Lanczky asked, "Are these the same children you started with? If you hadn't told me, I would have thought they were different."

Lanczky says, "I know how difficult it was for Wu and her choir. You can see it in the video — their conditions are not good, and the children's foundation is weak." She hopes Chinese teachers will remain open and willing to try new ideas — even just once.

Back at her urban school, Wu now focuses on making sure every child enjoys music. Her year in the countryside reflects the defining line of Kodaly's theory: "Music belongs to everybody." It is the birthright of every child, no matter where they are from.

Bai Shuhao contributed to this story.