Where did the folk songs of the Southern Dynasties come from?

In the literature of the Southern Dynasties, the folk songs of the Southern Dynasties are especially worth cherishing. It is mainly produced in Wu Ge and Xiqu in Jianye and Jingzhou. With short form and fresh and lively style, they praised people's pursuit of a better love life and their resistance to feudal ethics. Folk songs in the Southern Dynasties take love songs as their own music, showing a strong atmosphere of "street songs", which not only reflects the artistic taste of rulers, but also shows the influence of commercial development in the Yangtze River basin on poetry. Folk songs in the Northern Dynasties are the most successful part in the poetry of the Northern Dynasties. It directly inherited the tradition of Yuefu folk songs in Han Dynasty, including pastoral songs, love songs and battle songs, and widely reflected the social reality in the north and the life fate and spiritual temperament of the people in the north, forming a bold and vigorous style. The content and style of folk songs in the Northern and Southern Dynasties are different, but their isomorphism has become another climax of folk song creation after The Book of Songs and Han Yuefu, which has made gratifying achievements and made important contributions to the development of China's poetry.