opera. Bo (钹) The bo (bronze cymbals) were frequently used in Sui and Tang dynasties (AD 581–907) with varying designs. Now it is commonly made of high-tin bronze. The performer strikes the cymbals together. The most common type now is the jingbo (the prefix jing referring to Beijing, the prefix used to define the instruments in the Beijing opera). This type is clear and forceful in tone quality. It is also used in other regional opera genres and ensembles, and is one of the four major instruments (drum, large and small gongs and cymbals) in the jubilant luogu (锣鼓) (gong and drum) music. In local operas, the luogu ensemble often accompanies acrobatic fighting. Luo (锣) The luo, or Chinese gong, is made of high-tin bronze, hammered into the shape of a sifter. Its central resonating area can be either flat or convex. Its long history can be traced back to the early Western Han period (206 BC-AD 24) according to an archaeological find from a tomb of that period in Guangxi. In a text dating to the Tang period (AD 618–907), it was known as the shaluo (沙锣, lit. sand gong), which is among the earlier evidence of gong usage in classical literature. There are many varieties of gongs, each with varying tone qualities. The name is usually preceded by a prefix to specify each different kind. The largest type (over 120 cm in diameter) called dachaoluo, known for its deep and grave tone, is used in official settings like weddings, funerals and temple ceremonies. The smallest, the goujiaoluo (狗叫锣, lit. dog-calling gong), only 8 cm in diameter, can often be seen in theatrical ensembles in the southern parts of Fujian. Both the larger and the smaller boast distinct acoustic features, functions and performing styles. Different size and thinkness of the cymbals will affect the sound tone being produced. The da di luo (big gong) has a very deep sound in contrast to the goujiaoluo. Yunluo (云锣) The yunluo (yun, lit. cloud; luo, lit. gong) was first mentioned in historical records as yun'ao during the Yuan dynasty (1271–1368). The small gongs in a set, usually numbering up to 10 and in distinct pitches, are suspended vertically in a wooden frame. Each is attached to a cubicle within the frame, secured by cords. These gongs are all of the same diameter but vary in thickness. In terms of tuning, thicker dimensions