十二律各就其宫以起四声，而后六十律之声备，非以黄钟定为宫，太簇定为商，姑洗定
为角，林钟定为征，南宫定为羽也。如黄钟属子，子有五焉∶甲子征，丙子羽，戊子宫，庚子
角，壬子商，此黄钟五声也。大吕亦有五焉∶乙丑、丁丑、己丑、辛丑、癸丑，五音亦如之。余
律自寅至亥皆然。朱子曰∶律凡十二，各以本律为宫而生四律，如黄钟为宫，则太簇为商，
姑洗为角，林钟为征，南吕为羽，是黄钟一宫之声也。若林钟为宫，则南吕为商，应钟为角，
太簇为征，姑洗为羽，是林钟一宫之声也。（夫五音长短之序，则宫商角征羽；五时相生之序，则宫
征商羽角。故黄钟之宫作而林钟之征应，大吕之宫作而夷则之征应，天然妙合，不假人为，所谓同声相应者也。）
黄钟，干之初九；下生林钟，为坤之初六。林钟上生太簇，为干之九二；太簇下生南吕，
坤之六二。南吕上生姑洗，干之九三；姑洗下生应钟，坤之六三。应钟上生蕤宾，干之九
四；蕤宾下生大吕，坤之六四。大吕上生夷则，干之九五；夷则下生夹钟，坤之六五。夹钟
上生无射，干之上九；无射下生仲吕，坤之上六。如初九生初六，一阳一阴也，是为同位，
同位者象夫妻。初六生九二，一阴二阳也，是为异位，异位者象母子。所谓律娶妻而吕生子也。
The twelve pitch-pipes (Lü) each generate four additional tones based on their own Gong tone, thereby completing the sounds of the sixty pitch-pipes. This does not mean that Huangzhong is fixed as Gong, Taicu as Shang, Guxian as Jue, Linzhong as Zhi, and Nanyu as Yu. For instance, Huangzhong corresponds to the Earthly Branch Zi. Zi has five variations: Jiazi corresponds to Zhi, Bingzi to Yu, Wuji to Gong, Gengzi to Jue, and Renzi to Shang; these constitute the five tones of Huangzhong. Dalü also has five variations: Yichou, Dingchou, Jichou, Xinchou, and Guichou, with their five tones corresponding in the same manner. The same applies to all other pitch-pipes from Yin to Hai. Zhu Xi stated: "There are twelve pitch-pipes in total. Each pipe uses its own tone as Gong to generate four other pipes. For example, if Huangzhong is Gong, then Taicu is Shang, Guxian is Jue, Linzhong is Zhi, and Nanyu is Yu; this constitutes the sounds of the Huangzhong Gong mode. If Linzhong is Gong, then Nanyu is Shang, Yingzhong is Jue, Taicu is Zhi, and Guxian is Yu; this constitutes the sounds of the Linzhong Gong mode." (The sequence of the five tones by length is Gong, Shang, Jue, Zhi, Yu; the sequence of generation among the five seasons is Gong, Zhi, Shang, Yu, Jue. Therefore, when the Gong tone of Huangzhong sounds, the Zhi tone of Linzhong responds; when the Gong tone of Dalü sounds, the Zhi tone of Yize responds. This is a natural and exquisite harmony, requiring no human intervention, which is what is meant by 'like sounds respond to one another'.)
Huangzhong corresponds to the Initial Nine (Chu Jiu) of the Qian Hexagram; generating downwards produces Linzhong, which corresponds to the Initial Six (Chu Liu) of the Kun Hexagram. Linzhong generates upwards to produce Taicu, corresponding to the Nine at the Second Place (Jiu Er) of the Qian Hexagram; Taicu generates downwards to produce Nanyu, corresponding to the Six at the Second Place (Liu Er) of the Kun Hexagram. Nanyu generates upwards to produce Guxian, corresponding to the Nine at the Third Place (Jiu San) of the Qian Hexagram; Guxian generates downwards to produce Yingzhong, corresponding to the Six at the Third Place (Liu San) of the Kun Hexagram. Yingzhong generates upwards to produce Ruibin, corresponding to the Nine at the Fourth Place (Jiu Si) of the Qian Hexagram; Ruibin generates downwards to produce Dalü, corresponding to the Six at the Fourth Place (Liu Si) of the Kun Hexagram. Dalü generates upwards to produce Yize, corresponding to the Nine at the Fifth Place (Jiu Wu) of the Qian Hexagram; Yize generates downwards to produce Jiazhang, corresponding to the Six at the Fifth Place (Liu Wu) of the Kun Hexagram. Jiazhang generates upwards to produce Wuyi, corresponding to the Top Nine (Shang Jiu) of the Qian Hexagram; Wuyi generates downwards to produce Zhonglü, corresponding to the Top Six (Shang Liu) of the Kun Hexagram. Just as Initial Nine generates Initial Six, representing one Yang and one Yin, this is called "same position" (Tong Wei), where same positions symbolize husband and wife. Initial Six generates Nine at the Second Place, representing one Yin and two Yangs, this is called "different position" (Yi Wei), where different positions symbolize mother and child. This is what is referred to as "the Lü marries the wife (downward generation) and the Lü gives birth to the son (upward generation)."