Zhu Zaiyu (; 1536 – 19 May 1611) was a Chinese scholar, mathematician and music theorist. He was a prince of the Chinese

Ming dynasty The Ming dynasty, officially the Great Ming, was an Dynasties of China, imperial dynasty of China that ruled from 1368 to 1644, following the collapse of the Mongol Empire, Mongol-led Yuan dynasty. The Ming was the last imperial dynasty of ...

. In 1584, Zhu innovatively described the

equal temperament An equal temperament is a musical temperament or Musical tuning#Tuning systems, tuning system that approximates Just intonation, just intervals by dividing an octave (or other interval) into steps such that the ratio of the frequency, frequencie ...

via accurate mathematical calculation.

Biography

Zhu was born in Qinyang,

Henan Henan; alternatively Honan is a province in Central China. Henan is home to many heritage sites, including Yinxu, the ruins of the final capital of the Shang dynasty () and the Shaolin Temple. Four of the historical capitals of China, Lu ...

Province to an aristocratic family, the sixth-generation descendant of the

Hongxi Emperor The Hongxi Emperor (16 August 1378 – 29 May 1425), also known by his temple name as the Emperor Renzong of Ming, personal name Zhu Gaochi, was the fourth emperor of the Ming dynasty, reigning from 1424 to 1425. He was the eldest son of the Y ...

, the fourth emperor of the

Ming Dynasty The Ming dynasty, officially the Great Ming, was an Dynasties of China, imperial dynasty of China that ruled from 1368 to 1644, following the collapse of the Mongol Empire, Mongol-led Yuan dynasty. The Ming was the last imperial dynasty of ...

. Zhu inherited the title the Prince of Zheng in 1593, but quickly resigned it to his cousin. On the emperor's order, he was granted a new princely title in 1606, the year he delivered a set of ten musicological treatises to the court, establishing his scholarly merit. His posthumous name wa
鄭端靖世子
("His Excellency The Dauphin of Zheng"). Zhu wrote on music theory and temperament (five treatises survive), music history (two treatises survive), dance and dance music (five treatises survive), and several other works. Three music theory works in particular are associated with the ideas of equal temperament, the ''Lü Xue Xin Shuo''「律學新說」 ("on the equal temperament", 1584), ''Lü Lü Zheng Yi''「律呂精義」("A clear explanation of that which concerns the equal temperament", 1595/96), and ''Suan Xue Xin Shuo''「算學新說」("Reflection on mathematics", 1603). His work has been described as "the crowning achievement of two millennia of acoustical experiment and research" (Robinson 1962:224) and he is described as "one of the most important historians of his nation's music". File:乐律全书全-118.jpg, File:乐律全书全-119.jpg, File:乐律全书全-120.jpg, File:乐律全书全-121.jpg, Zhu Zaiyu's equal temperament ratio in ''Yue Lü Quan Shu''「樂律全書」 File:乐律全书全-122.jpg, File:乐律全书全-123.jpg, File:乐律全书全-124.jpg, Zhu also wrote treatises (three survive) on astronomy, physics, mathematics and calendrics, calculated the

magnetic declination Magnetic declination (also called magnetic variation) is the angle between magnetic north and true north at a particular location on the Earth's surface. The angle can change over time due to polar wandering. Magnetic north is the direction th ...

Peking Beijing, previously romanized as Peking, is the capital city of China. With more than 22 million residents, it is the world's most populous national capital city as well as China's second largest city by urban area after Shanghai. It is l ...

, the mass density of mercury and accurately described the duration of one

tropical year A tropical year or solar year (or tropical period) is the time that the Sun takes to return to the same position in the sky – as viewed from the Earth or another celestial body of the Solar System – thus completing a full cycle of astronom ...

to correct the Ming

calendar A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years. A calendar date, date is the designation of a single and specific day within such a system. A calendar is ...

. Zhu's work on equal temperament did not get any official recognition during his lifetime nor during the

Qing dynasty The Qing dynasty ( ), officially the Great Qing, was a Manchu-led Dynasties of China, imperial dynasty of China and an early modern empire in East Asia. The last imperial dynasty in Chinese history, the Qing dynasty was preceded by the ...

. This was due to the Ming and Qing emphasis on classical scholarship and discouragement of ideas based on empirical observation rather than textual interpretations.

Biography

See also

References

Further reading