Chapter 53 Zhu Zaiyu/Inventor of the Twelve Equal Laws

Zhu Zaiyu (1536-1611), courtesy name Boqin, was born in Qushan.His ancestral home is Fengyang County, Anhui Province, and he was born in Hanoi County, Huaiqing Prefecture (now Qinyang, Henan Province).He is the ninth grandson of Ming Taizu Zhu Yuanzhang.Famous law scholars (known as "Lüsheng"), calendar scholars, mathematicians, and art scientists in the Ming Dynasty. Zhu Zaiyu's father, Zhu Houtan, was the King of Zheng Gong. He was good at calligraphy and prose, and was proficient in rhythm. Zhu Zaiyu was deeply influenced by him since he was a child.He is very smart and likes music and mathematics.In the twenty-fourth year of Jiajing (1545), Zhu Zaiyu, who was only ten years old, was named the eldest son.His father was deprived of his title due to false accusations, and was imprisoned in Fengyang, Anhui. Zhu Zaiyu therefore built an earthen house outside the palace gate, "Xigao lived alone for nineteen years".Later, when his father was rehabilitated, he could take over the title of king, but he resigned firmly in the eunuch, and it took seven times in fifteen years before he was granted permission.From then on, he concentrated on reading and writing, and lived his life as a scholar.

Zhu Zaiyu had a deep research on the calendar and rhythm, and wrote forty volumes of "The Complete Book of Music and Rhythm".His greatest contribution is the creation of the twelve equal temperaments, which is an epoch-making great invention, which solves the big problem that the old temperament system can't rotate palaces and tunes well, which has plagued countless musicologists since ancient times.His achievements were decades earlier than those of the West, and they caused a great sensation after they were introduced to the West.Many modern musical instruments and performances use twelve equal temperament.It is a pity that his research results have not been taken seriously in China.The famous British scholar Joseph Needham said that Zhu Zaiyu was "the creator of the world's first equal law number".And lamented his obscurity in the history of Chinese music and science and technology, "This is really incredible irony" (Volume 4 of "History of Science and Technology in China").