I hope you have a few minutes to listen to listen to Liane, Amy, and Katie below. They are members of the Kwong Kow Chinese School Dulcimer Ensemble. The school is located in Boston and teaches Chinese language, art, and culture.
The question of how the dulcimer, or yangqin, arrived in China is a mystery. There are three theories noted in Wikipedia, which I excerpt here.
One theory is that the yangqin came into contact with the Chinese through the Silk Road. The Silk Route stretches almost 5,000 miles reaching from China to the Middle East, including Iran (Persia). The Iranian santur, a dulcimer, has existed since ancient times. If any dulcimer was to influence China by land, it is likely to be this instrument. It is somewhat smaller in size, is same in shape, and is also played using two wooden mallets.
Here's the second theory. During the 16th century, the Age of Exploration in Europe reached its climax, and soon trade was established between China and Europe. Portuguese trading in Chinese waters began in the 1500s. Music historians report that the salterio, a hammered dulcimer, was played in Portugal, Spain, and Italy during this period. Thus, it is possible that the yangqin originated when the Portuguese, the English or the Dutch brought a dulcimer player to China who performed for locals.
The final theory that some music scholars support is the theory that the yangqin was developed within China itself, devoid of all foreign influence. These historians state two possible explanations for the instruments native origin. One is that the yangqin is a development from an ancient string instrument called zhu. The other is that the yangqin originated from Yangzhou, China itself.
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