Engineering trumpets are used in ramming, digging, logging, quarrying and other labors. The intensity and speed of labor determine the singing and rhythm of engineering chants. When the labor intensity is low, the melody of the haozi is free and bold; when the labor intensity is high, the melody of the haozi appears rough and heavy. In the intense and tense labor, the rhythm of haozi music is fast and powerful, the melody is simple, and sometimes there are even simple call signs. The artistry of the tune is inversely proportional to the labor intensity, which is a common feature of haozi music. It is a tool used when breaking foundations or driving piles. It is usually a round stone or discus, with holes drilled around it and a few ropes tied around it. During the beating, several people pulled me up by the rope and then smashed me to the ground. "Dahong Song" in Changde, Hunan Province is high-pitched and loud. The lyrics are improvised and sung according to the labor situation. It not only directs the labor, but also pays attention to regulating the emotions of each worker to mobilize everyone's enthusiasm. Some plow the fields and shout cow horns, There are chants for shouting cows, chants for carrying trees, and chants for building walls; chants for pulling carts, and chants for digging mountains and stones in rural areas; chants for beating rams in the Marquis of Min; and chants for pulling wood in Yongtai, etc. Some chants may have no substantive words, just workers' call signs, which are used to unify the rhythm of work and inspire enthusiasm for work.