It's hard to imagine how difficult it is for blind people to learn piano tuning. Cai Qionghui spends 13 or 4 hours a day by the piano, carefully touching each part by hand, and carefully memorizing each position carefully. An ordinary piano has more than 8,000 parts, and a grand piano has 13,000 parts, many of which are barbed and barbed. Cai Qionghui's ten fingers are often bloodied. It took Cai Qionghui a whole year to accurately memorize the position of all the parts of the piano. Among the 88 black and white keys and 230 strings, even a 0.1 mm error can cause piano pitch deviation. Cai Qionghui's job is to find out the crux of the problem and correct it from 88 black and white keys, 230 strings and 8000 parts.There are a total of 60 pianos in the school. Cai Qionghui has touched almost every piano, and every piano has been tuned, so that she can hear the resonance caused by a loose screw on each piano. Kung Fu pays no attention to people, Cai Qionghui tunes a piano in four hours from the beginning, tunes a piano in an hour, and finally tunes a piano in twenty minutes. After four years of practice, Cai Qionghui fully mastered all the techniques of piano tuning, and graduated with the best score in the school for professional courses.