In the Zhou dynasty, King Wen of Zhou added a sixth string for his son King Wu of Zhou to encourage his army to fight with the Shang.

周文王为他的儿子周武王增加了第六根琴弦，鼓励他的军队与商朝作战。

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King Wu of Zhou, added a seventh string to encourage his army to fight with the Shang.

周武王增加了第七根弦，以鼓励他的军队与商朝作战。

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