Shin-Yi Yang 

is a 21-stringed Chinese zither that has about 2,500 years of history. In the ancient time it was played by court and folk musicians.
Zheng is an ancient Chinese instrument. It has been developed from a small instrument made from bamboo, originally used by herdsmen. It was very popular during the ancient times, as early as the Chinese Warring States times and the Chinese Ch'in Dynasty (255BC-206BC and earlier). Therefore another commonly used name of Zheng is Gu Zheng ("ancient" pounced "Gu" in Chinese). The zither has a horizontal wooden box resonator. The resonator has an arched surface and is elongated-trapezoidal with 13 to 21 strings stretched over individual bridges. Although metal strings are common today, the strings of Zheng were of silk in the ancient days. The plucked zither rests on two pedestals and is played using 3 to 4 imitation nails. On the right side of the bridges, both hands may pluck the strings and on the left side, the left fingers bend the strings to change pitch or to provide embellishment. Its playing range spans three to four octaves. Zheng is a distinguished solo instrument and an accompaniment instrument for ballad singing. In the Chinese orchestra, the zheng is employed when special an effect such as the descending strains of cascading water is required. Its attraction lies on a water-rippling sound produced when its strings are plucked by fingers in a sweeping manner from the highest note to the lowest note or vice versa.