In 2016, only two years after Guo began teaching, the school was made the provincial center for accordion playing, and since then, students have won first prizes in five provincial accordion competitions.

In 2018, Mirco Patarini, president of the Confederation Internationale des Accordeonistes, a global entity encompassing national accordion organizations from around the world, came to watch a performance. And in 2019, Xun Xinrui, one of the first to study under Guo, got 92 out of 100 in her college entrance exam for the accordion.

From not knowing what a stave is to taking part in the national college entrance exam for art, the influence of music on Shuangshiping's students has been slow but profound.

Gradually, they've also begun to play other instruments, such as the hulusi (a gourd flute) and the guzheng (a plucked zither).

"Every time I come to teach, I'm happy and I enjoy myself," Guo said. "And if I can help in any way, it makes me feel young again."

While some parents worry about what might happen if Guo stops teaching, the accordion master is way ahead of them.

In addition to training students, he's also training teachers to take over when he is not available.

After the school was granted its status as an accordion center, more funding arrived for instruments.

"It is difficult to ask these students to pay for something like an accordion, but if they are given the opportunity to play one, they can seize it," Guo said.

Guo recalled one particularly memorable moment.

"One day, we took 200 students to Changsha to perform at the Hunan Concert Hall, one of the best venues in the province," he said.

Now, 95 percent of the students at the school are able to play an instrument of some kind.

"We will continue to help more students realize their musical dreams," said Xun Mengxiong, current headmaster of Shuangshiping.

Zhu Youfang contributed to this story.