Yin and Yang in Equal Measure: The Way of Central Harmony and the Equilibrium of Day and Night at the Spring Equinox
This article offers a multi-dimensional exploration of the Spring Equinox (Chunfen) among the Twenty-Four Solar Terms, drawing on pre-Qin Confucian and Daoist philosophy, the original meanings of Chinese characters, and astronomical phenomena. By analyzing the character 'fen' (divide/equalize), the sun's alignment with the equator, and seasonal signs such as the return of swallows and the onset of thunder, it reveals the profound wisdom of 'central harmony' and the unity of Heaven and humanity embedded in the equinox's equal days and nights.
Chapter Sixteen: Music and Calendrics -- The Jiazhong Pitch-Pipe and "Unifying Pitch-Pipes with Measures and Standards"
I. Jiazhong: The Pitch-Pipe of Mid-Spring
The Monthly Ordinances states for mid-spring: "Its note is jue; its pitch-pipe is Jiazhong." This chapter explores the significance of Jiazhong, the pitch-pipe of mid-spring.
Ancient China had "twelve pitch-pipes" (shi'er lu) -- twelve standard pitches dividing an octave into twelve not-quite-equal semitones: Huangzhong, Dalv, Taicu, Jiazhong, Guxian, Zhonglv, Ruibin, Linzhong, Yize, Nanlv, Wuyi, and Yingzhong. These twelve pitch-pipes correspond one-to-one with twelve months. This correspondence, called "pitch-calendar" (luli), is China's exquisite system for linking musical pitch with calendrical reckoning.
The name "Jiazhong" carries deep meaning. Jia can mean "to flank," "to be in the middle," "to be bracketed between." In the twelve-pipe sequence, Jiazhong falls between Taicu (first month) and Guxian (third month), occupying the center. More deeply, jia hints at "yin and yang flanking each other" -- at the Spring Equinox, yin and yang are in equal halves, the two qi "flanking" each other in equilibrium, resonating with the jia in Jiazhong.
II. The Unity of Pitch and Calendar: Resonance Between Sound and the Seasons
Why did the ancients correlate the twelve pitch-pipes with the twelve months$25 Behind this lay an exceedingly profound cosmology: pitch and season, sound and the qi of Heaven and Earth, are interconnected and in resonance.
This "unity of pitch and calendar" even gave rise to the famous practice of "testing the qi" (houqi). The ancients believed that if the twelve pitch-pipes were buried in the earth in a certain manner with their tubes filled with ashes of reed membrane, then when a given month arrived and the qi of Heaven and Earth matched the corresponding pipe, the ashes in that pipe would be "blown out" by the earth's qi. Though scientifically unfounded, this practice vividly reflects the ancients' deep conviction that pitch and the qi of Heaven and Earth resonate together.
III. "Unifying Pitch-Pipes with Measures and Standards": The Convergence of Music and Fairness
The unity of pitch and calendar extended further to the unification of measures and standards -- the famous "unifying pitch-pipes with measures and standards" (tong lu duliangheng).
The Book of Documents, "Canon of Shun," records: "He harmonized the months and corrected the days, and unified the pitch-pipes with the measures and standards." Why should pitch-pipes be linked with weights and measures$1 Because in ancient China, the standards for weights and measures were often derived from pitch-pipes (especially the Huangzhong pipe) -- the length of the Huangzhong pipe defined the standard of length, its capacity defined the standard of volume, and the weight of the millet grains it held defined the standard of weight. Pitch-pipes thus became the "source" and "baseline" of all measures and standards.
And all of this resonates deeply with the Spring Equinox's "when day and night are equal, unify measures and standards." Pitch (Huangzhong), measures and standards (unified measures), and the Way of Heaven (equal days and nights) are linked through the core spirit of "equilibrium," "standards," and "fairness" into one. The harmony of pitch (he), the accuracy of measures (zhun), and the equality of the Way of Heaven (jun) are manifestations of the same spirit of "central harmony and equilibrium" at the levels of sound, instruments, and astronomy.
IV. "Music Is the Harmony of Heaven and Earth": The Central Harmony of Musical Pitch
The Book of Rites, "Record of Music" (Yueji), states: "Music is the harmony of Heaven and Earth; rites are the order of Heaven and Earth." Music is defined in terms of Heaven and Earth's harmony, and the Spring Equinox is the most thorough temporal manifestation of that same harmony. The Record of Music further states: "The greatest music shares the same harmony as Heaven and Earth; the greatest rites share the same regularity as Heaven and Earth." When the ancients in mid-spring sounded the Jiazhong pitch-pipe in resonance with the qi of Heaven and Earth, they sought to bring human music's "harmony" into accord with the seasonal "harmony" of the Spring Equinox, attaining the supreme state of "the greatest music sharing the same harmony as Heaven and Earth."