 The excavation of Bianzhong, a typical and royal instrument found in ancient China, emphasizes the development of complex music systems in Han Dynasty.The set of Bianzhong can vary in many cases; for example, a specific excavation of Bianzhong from Jiangsu Province include different sets of bells, like Niuzhong and Yongzhong bells, and many of them appear in animal forms like the dragon, a traditional Chinese spiritual animal.Shang bronzes became appreciated as works of art from the Song dynasty, when they were collected and prized not only for their shape and design but also for the various green, blue green, and even reddish patinas created by chemical action as they lay buried in the ground.