It points out that the position of the maximum strain, stress and tension is at first group trough type roller, not at passing poion of pulley if the head drum works as pulley.

The connotation of passion of loessial ground does not only rely on the inner tension of rich drum dancing sports culture, but also the unique passion rooting in the loessial ground.

A large copper or brass hemispherical drum with a parchment head that can be tuned by adjusting the tension.