Guzeng 古箏, one of the oldest Chinese and Asian zithers. With the Guqin and the Mongolian Yatga, the Guzeng has the greatest influence on the diversity of the zithers in Asia. The Guzheng is proven up to the 5th century BC. Since then it has changed several times in shape and number of strings. Today's "classic" Guzheng has 21 strings.