For example:
The monks in the temple are all farmers, and they are already in the west. Seeing the Taoist priest holding a bowl, shovel and hat, he sang wild songs and went home. (Yuan Zhongdao's Ten Records of Xishan)
Monks work like farmers and sing country songs on their way home from work at night. Compared with urban artists' songs, literati's songs, court music and country songs, it is called wild songs. Wilderness means countryside and fields. Of course, the style of wild songs is rough.
In addition, some poems written by literati describing the countryside are titled "Folk Songs". For example:
Wild folk songs (Tang)
Crow feather arrow mountain sang bow, face upwards shot down the title of Lu Hong.
Hemp clothes are black and fat. They pounce on the north wind and bring wine to the fields in the evening.
People's hearts are not poor, and glory is not equal to anger.
The cold wind has turned into spring willow, and the rows are full of smoke.