Confucius one day played the qin, a seven-stringed plucked traditional Chinese musical instrument, at home. Min Zi, one of Confucius' disciples, said to another disciple Zeng Zi, " The melody the Master played before was clear and harmonious with beautiful artistic conception, but now it is quieter and more secluded. What's happened?" They asked Confucius and talked about their feelings towards the melody. Confucius said, "Just now I happened to watch that a cat was stealthily preying on a mouse, so my mood of playing the qin changed accordingly."