唐礼乐志曰∶声无形而乐有器。古之作乐者，知夫器之必有敝，而声不可以言传，惧夫
器失而声遂忘也，乃多为之法以着之，故求声者以律，而造律者以黍。自一黍之广，积而为
分寸，一黍之多，积而为龠合，一黍之重，积而为铢两，是三物者亦必有时而敝，则又总其法
而着之于数，使其分寸龠合铢两皆起于黄钟，然后律度量衡相用为表里，使得律者可以制
度量衡，因度量衡亦可以制律，此古君子知物之终始，而忧世之虑深，其多为之法而丁宁纤
悉，可为至矣。然黄钟之律生于尺，而尺乃生于黍，累黍造尺，不过三法，皆自古有之。曰
横黍者，一黍之广为一分也；曰纵黍者，一黍之长为一分也；曰斜黍者，非纵非横而斜倚相
排也。凡黄钟之长，以横黍言之，则为一百分，太史公所谓子一分是也；以纵黍言之，则为
八十一分，淮南子所谓其数八十一是也；以斜黍言之，则为九十分，前后汉志所谓九十分是
也。三法虽异而律则同也。择黍之法，以上党境内土地肥处产者为佳，即今之糯小米，俗
名黄米者是也。郑世子曰∶古上党郡，即今山西潞安州，境内产五色黍。其黑色黍亦有数
种∶软黍堪酿酒者名 ，硬黍堪炊饭者名 ，一稃内两颗黍名 。律家所用，惟 而已。古
云取 黍中者，盖谓中用之黍，非中等之谓，如俗语选物曰中用不中用，亦非指中等也。或
曰中字读去声，谓中式也，其义亦通。诗曰∶诞降嘉种，惟 惟 。既用一嘉字，其义可见，
则知异常者方为嘉种，且 之为言巨也，盖谓最大者为佳。黍大则尺大而黄钟之声遂浊，
黍小则尺小而黄钟之声遂清，夫黄钟之音宫音也，最长最浊，是其本体，然则黍之最大者乃
为真 黍耳。后人不知此理而泥于汉志中黍之文，遂致所累之尺短，所造之乐哀，非中和
之音矣，此不可不辨也。（龠音药。 音巨。 音祭。稃音夫。 ，飘米切。）
《唐书·礼乐志》说：声音没有形体，而音乐（乐）有具体的器物。古代制作音乐的人，知道器物必定会损坏，而声音无法通过语言完全传达，担心器物失传后音乐也随之被遗忘，于是制定了多种方法来记录它。因此，寻求音律标准依据的是“律”，而制造“律管”的依据则是黍米。
从一颗黍米的宽度积累起来成为寸和分，一颗黍米的容量积累起来成为龠和合，一颗黍米的重量积累起来成为铢和两。这三种度量衡单位也必定会随着时间磨损或改变，于是又总结这些方法并将其数字化，使寸、分、龠、合、铢、两都起源于黄钟律管的标准。这样一来，律、度、量、衡相互依存，互为表里，使得懂得制律的人可以制定度量衡，反过来通过度量衡也可以制定律管。这是古代的君子深知事物的始终规律，对世事的忧虑深远，他们制定各种方法详尽细致，可以说是达到了极致。
然而，黄钟律管的长度源于尺，而尺又是根据黍米制定的。累积黍米来制作尺子，不过有三种方法，这些都是自古就有的。第一种叫“横黍”，即一颗黍米的宽度作为一分；第二种叫“纵黍”，即一颗黍米的长度作为一分；第三种叫“斜黍”，既不是纵向也不是横向，而是斜着倚靠排列。
关于黄钟律管的总长度：如果用“横黍”来计算，就是一百分，这就是太史公（司马迁）所说的“子一分”的意思；如果用“纵黍”来计算，就是八十一分，这就是《淮南子》所说的“其数八十一”的意思；如果用“斜黍”来计算，就是九十分，这就是前后《汉书·律历志》所说的“九十分”的意思。这三种方法虽然不同，但所定的律管标准是一致的。
选择黍米的方法，以上党地区土地肥沃处出产的为佳，也就是现在的糯小米，俗称黄米。郑世子说：古时的上党郡，就是现在的山西潞安州，境内出产五色黍米。其中黑色的黍米也有几种：软性黍米适合酿酒的名为“秬”（jù），硬性黍米适合做饭的名为“稷”（jì），一个谷壳内有两颗黍米的名为“穄”（jì）。律学家所使用的，只有“秬”这一种罢了。
古人说取“中”黍，大概是指中间大小适宜使用的黍米，而不是指中等等级的黍米。就像俗语中说选物是“中用”还是“不中用”一样，也不是指等级中等。有人说“中”字读去声，意为“符合标准/中式”，这种解释也是通顺的。《诗经》说：“上天降下好种子，只有秬和秠。”既然用一个“嘉”（美好）字来形容，含义就很明显了，那么可知非同寻常的才是好种子。而且“秠”（pī）的意思是巨大，大概是指最大的那种为最佳。
黍米如果太大，制作的尺就会大，黄钟发出的声音就会低沉浑浊；黍米如果太小，制作的尺就会小，黄钟发出的声音就会清亮尖锐。黄钟之音属于宫音，是最长且声音最低沉浑浊的，这才是它的本体特征。既然如此，那么最大的黍米才是真正的“秬”黍。后人不知道这个道理，拘泥于《汉书·律历志》中关于“中黍”的文字记载，导致所累积的尺偏短，所制作的音乐音调悲哀凄切，不再是中和的声音了。这一点是不可不辨明的。（龠，读音同药。秬，读音同巨。稷，读音同祭。稃，读音同夫。秠，拼音切音为飘米。）
The *Treatise on Music and Ritual* of the Tang Dynasty states: "Sound is formless, whereas music (Yue) has instruments." The ancients who created music understood that instruments would inevitably deteriorate, while sound could not be fully conveyed through words. Fearing that if instruments were lost, the music would also be forgotten, they devised numerous methods to record it. Thus, those seeking pitch standards relied on *Lü* (pitch pipes), and those crafting *Lü* pipes relied on millet grains.
From the width of a single millet grain, units such as *cun* (inch) and *fen* (line) were accumulated; from the volume of a single millet grain, units such as *yue* (a measure of capacity) and *he* (a smaller unit of capacity) were accumulated; and from the weight of a single millet grain, units such as *zhu* (grain-weight) and *liang* (tael) were accumulated. Since these three types of measurements would also eventually wear out or change, their methods were summarized and codified into numbers, ensuring that *cun*, *fen*, *yue*, *he*, *zhu*, and *liang* all originated from the standard of the *Huangzhong* (Yellow Bell) pitch pipe. In this way, *Lü* (pitch), *Du* (length), *Liang* (capacity), and *Heng* (weight) served as inner and outer counterparts to one another. This allowed those skilled in making pitch pipes to establish standards for length, capacity, and weight, and conversely, those with standards for length, capacity, and weight could establish pitch pipes. This demonstrates that ancient sages understood the beginning and end of things, harboring deep concerns for the world. Their meticulous and detailed formulation of methods was truly exemplary.
However, the length of the *Huangzhong* pipe was derived from the *chi* (foot/ruler), which in turn was derived from millet grains. Accumulating millet grains to create a ruler involved only three methods, all of which existed since antiquity. The first is called "transverse millet" (*heng shu*), where the width of one millet grain equals one *fen*; the second is called "longitudinal millet" (*zong shu*), where the length of one millet grain equals one *fen*; and the third is called "diagonal millet" (*xie shu*), where grains are arranged diagonally, leaning against each other.
Regarding the total length of the *Huangzhong* pipe: expressed in terms of transverse millet, it is 100 *fen*, which corresponds to Sima Qian's statement of "one *zi* equals one *fen*"; expressed in terms of longitudinal millet, it is 81 *fen*, corresponding to the *Huainanzi*'s statement that "its number is eighty-one"; and expressed in terms of diagonal millet, it is 90 *fen*, corresponding to the statements in the *Book of Han* and *Book of Later Han* regarding "ninety *fen*." Although these three methods differ, the resulting pitch pipe standard is the same.
The method for selecting millet is that grains produced in fertile lands within the Shangdang region are considered superior. These are essentially glutinous millet, commonly known as yellow millet. Prince Zheng stated: Ancient Shangdang Commandery corresponds to modern Luzhou Prefecture in Shanxi Province, where five-colored millet varieties grow. Among them, black millet has several subtypes: soft black millet suitable for brewing wine is called *Ju* (black millet); hard black millet suitable for cooking rice is called *Ji* (millet); and millet with two kernels per husk is called *Ji* (foxtail millet). Musicians and theorists used only *Ju*.
The ancient saying "select the middle millet" refers to millet that is centrally sized for practical use, not millet of an "average" grade. This is similar to the colloquial expression asking whether an item is "useful" (*zhong yong*) or not, which does not refer to average quality. Some argue that "Zhong" should be pronounced with the departing tone, meaning "standard-compliant," which is also a valid interpretation. The *Classic of Poetry* states: "He sent down fine seeds, only *Ju* and *Pi*." The use of the character "Jia" (fine/excellent) makes the meaning clear: only exceptional varieties are considered fine seeds. Furthermore, "Pi" implies "large," indicating that the largest grains are the best.
If millet grains are too large, the resulting ruler will be long, causing the *Huangzhong* pitch to be low and muddy; if millet grains are too small, the resulting ruler will be short, causing the *Huangzhong* pitch to be high and clear. The note of *Huangzhong* belongs to the Gong (Palace) mode, characterized by being the longest and having the lowest, most resonant tone; this is its essential nature. Therefore, the largest millet grains constitute the true *Ju*. Later generations, unaware of this principle, rigidly adhered to the text in the *Book of Han* regarding "middle millet." Consequently, the rulers they constructed were too short, and the music they produced sounded mournful rather than harmonious and balanced. This discrepancy must be clarified.
(Note: *Yue* is pronounced like "yao". *Ju* is pronounced like "ju". *Ji* [hard millet] is pronounced like "ji". *Fu* means husk. *Pi* is pronounced via the fanqie spelling "piao-mi".)