What exactly does Lu's exposition of primitive people's songs and dances in Spring and Autumn Ancient Music describe?

For the diseases caused by such an environment and such a life, the ancestors not only had a certain understanding, but also had ideas and measures to resist and prevent them. For example, health care measures such as living in a house have been mentioned above. Here, I only quote the discussion about primitive people's songs and dances in Lu's "Spring and Autumn Ancient Music": "At the beginning of Tao and Tang Dynasties, yin and qi were stagnant and the waterways were congested, which was not original. The people are depressed and stagnant, and their bones and muscles can't reach them, so they use this as a dance to preach. " This statement gives people a very real and scientific feeling. It truly describes that ancient people lived in a dark and humid environment, which made people mentally stagnant and suffered from wind-cold-dampness arthropathy. Admirable people use dance to exercise the muscles and joints of the human body to prevent these common diseases. The occurrence and development of guided massage in China is closely related to the dance that people used to prevent and treat diseases in primitive society. The massage and guiding techniques used in medical treatment have always been closely related to the martial arts that people exercise and keep fit. Massage and guidance are not only used for muscle stiffness and joint strain caused by excessive physical labor, but also for injuries and dislocations caused by fighting with wild animals or war. In primitive society, our ancestors gradually realized that these joyful songs and dances had a good effect on personal health and prevention and treatment of the above diseases. From unconscious to conscious understanding and dissemination, massage, guidance and external treatment were gradually born.