Chapter Sixteen: Chushu and Musical Tuning — The Yize Pitch and Autumn's Solemn Sound

I. The Twelve Pitches and Twelve Months: Yize Paired with the First Month of Autumn

In the cosmological system of the pre-Qin era, musical tuning corresponds with precision to months and solar terms. The twelve pitches pair with the twelve months; the first month of autumn (the seventh month, the shen month) in which Chushu falls corresponds to "Yize" among the twelve pitches.

The Liji Yueling explicitly records: "In the first month of autumn, the pitch corresponding is Yize" — the vital breath of this month resonates with the vibration frequency of the Yize pitch.

II. The Deep Meaning of the Name "Yize"

The two characters of "Yize" (夷則) themselves embody the spirit of early autumn and Chushu.

Yi (夷) carries the meanings of "level," "wound," "kill," and "destroy." Ze (則) means "rule," "standard," "model." Taken together, "Yize" conveys: in the seventh month, yin energy carries out its severity (yi), and all things should accord with the rule (ze) of gathering in and storing away.

This perfectly matches Chushu's spirit of "heaven and earth begin their solemnity": yi's "wounding and killing" is the solemn vital breath; ze's "rule and standard" is the Way that all things should follow in gathering and storing. The ancients named the seventh month's pitch "Yize" with full awareness of this month's cosmic breath — it is severe (yi) yet principled (ze); it fells all things while simultaneously establishing for them the rule of measured withdrawal.

III. Why Does Music Correspond to the Seasons$23

The answer lies in the ancients' conviction that "heaven, earth, and all things are constituted by vital breath and each has its own rhythm of vibration." Since both the vital breath of heaven and earth and sound are forms of "vibration," a "resonance" can exist between them — a particular pitch-pipe happens to match the vibrational frequency of the vital breath prevailing in a particular season.

IV. The Shang Note, Yize, and the Solemn Sound of Autumn

The first month of autumn is both "its note is shang" (from the pentatonic scale) and "the corresponding pitch is Yize" (from the twelve pitches). These two perspectives — "tone" and "pitch" — differ in angle but converge in spirit: both point toward autumn's "solemn, cool, restraining sound-character." The shang's "sorrow" and Yize's "wounding" echo one another — autumn's sound, whether viewed through the five tones or the twelve pitches, is a sound of "sorrow," "severity," "solemnity," and "grief," perfectly unified with "heaven and earth begin their solemnity" and the literary tradition of "autumnal sorrow."

V. Music as the Medium of Communication Between Heaven and Humanity

The Liji, "Yue Ji" (Record of Music), says: "Music is the harmony of heaven and earth; ritual is the order of heaven and earth." And: "Great music shares its harmony with heaven and earth; great ritual shares its rhythm with heaven and earth." In the ancients' view, music is the solemn medium through which humans communicate with and respond to the vital breath of heaven and earth. The solemn and austere Yize and shang tones of Chushu are not merely mimicry of autumn's atmosphere but the bridge through which humans "share harmony with heaven and earth" and join in autumn's rhythm of gathering-in.