It’s called Canghai.

Song is an art form that combines lyrics and music score, and it is also a form of expression. The lyrics and music correspond one to one. There are generally three ways to create songs: one is to first have words and then compose the music based on them; the other is to write the music first and then the words, and then fill in the words according to the sound; the third is to re-compose the words and music based on the existing music or words, which is an adaptation or cover.

Songs are the smallest and shortest musical art form, forming one of the earliest and most influential music art forms. Songs have been with the origin of human civilization from the beginning, and have spent a long time together. During the long and difficult years, songs took deep roots. This popular form of artistic performance is a way for people to cultivate their sentiments.

Source of the tune:

The tune is the original name of Ci. The collection of Ci that was discovered in Dunhuang in 1898 and was mainly created in the prosperous and mid-Tang Dynasty is called "Yun Yao Ji Za Za" "Tune", this tune is not a record of the score, but a collection of lyrics. It can be seen that the tune is used as the name of the second seat.

Bai Juyi wrote in the tune "Recalling Jiangnan" that this song is also called "Xie Qiuniang". As a name for a ci style, tune was not only popular in the flourishing and mid-Tang dynasties, but was still used on some occasions after the ci style had other new names.