Introduction to underground opera: Tunpu underground opera is primitive and rough, and reflects the war vividly. It is known as the "living fossil of drama". Earth Opera, commonly known as Tiao Shen, was first evolved from Jun Nuo Opera. It originated in the Yin and Shang Dynasties and has a history of more than 3,000 years. The main forms of expression of the drama are singing and dancing. The content is mostly about loyalty to the emperor and serving the country on the battlefield. The singing is high-pitched and sad, with the original Yiyang tune of the ancestors of Peking Opera, inspiring the descendants of Tunbao to serve the country.