If this phenomenon has always been there, then there must be some expressions in the old songs. For this reason, I found Wu Keyong, the inheritor of Dong songs in Huaihua, and he helped me to search the old songbook in his home, while his father told me that the song of "Yin and Yang" that I asked about needs three or four hours of singing, which Yongke could not sing. The lyrics say that, “Tonight we are gathered to sing a song for you, please be quiet when listening to my singing; we come to this world but few of us can fulfill our dreams, just like the short and tall hills are never the same. There are food and clothing doomed for us, and our life length is also doomed. Raising boys and girls depends on their birthday horoscopes, while family wealth and land are determined by the good deeds done in past life. Your husband or wife is also determined by fate. Someone did not believe in what Isaid, and heasked the underworld Yama about this. There are always people who have been to the underworld and talk about it in this world.” This song talks about six stories about Yin and Yang, at the end of the song it says, "My friends can sing good songs, but I have no good songs to sing, so I have to sing Yin and Yang.”
I believe that there are many such songsin Dong folk, and there are many such stories that have never discontinued for thousands of years.