Rotting Grass Transforms into Fireflies: The Philosophy of Metamorphosis and the Earth Virtue of Late Summer in the Great Heat
This article offers a deep reading of Great Heat (Dashu), the twelfth of the twenty-four solar terms, through the lenses of pre-Qin Confucian and Daoist philosophy, classical etymology, and astronomical phenology. It reveals the cosmic significance of the sun reaching ecliptic longitude 120°, when summer heat attains its zenith, and explores the Earth virtue of late summer, the metamorphosis of rotting grass into fireflies, and the hexagram Dun with its two rising yin lines — illuminating the ancient wisdom of reversal at the extreme and counterbalancing excess.
Chapter Sixteen: Great Heat and Musical Tuning — The Sound of Linzhong
I. The Twelve Pitch-Pipes and the Twelve Months: Music and Calendar in Correspondence
In the pre-Qin cosmology, musical tuning and the calendar stand in mutual correspondence — this is "the correspondence of pitch-pipes and calendar" (luli xianying). The twelve pitch-pipes (Huangzhong, Dalü, Taicu, Jiazhong, Guxian, Zhonglü, Ruibin, Linzhong, Yize, Nanlü, Wuyi, Yingzhong) correspond one-to-one with the twelve months.
The Monthly Ordinances records for the sixth month (in which Great Heat falls): "The pitch-pipe that accords is Linzhong."
II. The Sound of Linzhong: Fire and Earth Intertwined
Linzhong occupies a special position among the twelve pitch-pipes. In the five-tone system, Linzhong corresponds to the gong tone and to Earth. Thus a deeply suggestive phenomenon appears: the sixth month (late summer) as a whole belongs to "Fire" (its tone is zhi), yet the pitch-pipe it "accords with" — Linzhong — corresponds to the gong tone and to Earth!
This "Earth-tone within a Fire-season" is no accident; it once again confirms the special nature of "late summer Central Earth." The sixth month, though superficially Fire (summer's coda), is in substance the time when Central Earth presides. Therefore its pitch-pipe "accords with Linzhong" (corresponding to gong/Earth) — the musical confirmation of "late summer Earth flourishing."
The tonal quality of Linzhong — deep, steady, broad — perfectly accords with Earth virtue's depth, stillness, and breadth. In Great Heat, when fire energy is most agitated and people most prone to restlessness, Linzhong's deep, steady sound seems heaven-earth's "acoustic remedy" to settle and harmonize that restless fire energy.
III. The Cosmology of Musical Tuning: Sound and Energy in Resonance
Why did the ancients build this system of correspondence between pitch-pipes and calendar$16 Behind it lies an extraordinarily bold conviction: sound and energy resonate (shengqi xiangying). Each month, each solar term possesses its specific vibrational frequency, its specific "energy quality"; and each pitch-pipe possesses its specific frequency and "tonal quality." When the month's energy and the pipe's tone are in accord, they resonate.
And "pitch-pipes harmonize virtue" (lü yi he de) — music possesses the power to harmonize character and transform the human heart. The Record of Music (Yueji) in the Book of Rites says: "Music is the harmony of heaven and earth." Through a single tone, Linzhong unites the three powers — heaven (earth-energy), earth (Earth virtue), and humanity (the disposition of the heart) — the ultimate expression of "music in harmony with heaven and earth."