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。
十二律各自以本律为宫音来衍生出四种其他声调，这样六十律的声音才完备。这并不是指固定地以黄钟定为宫、太簇定为商、姑洗定为角、林钟定为徵、南吕定为羽。例如黄钟对应地支子，子在五行天干中有五种情况：甲子属徵，丙子属羽，戊子宫，庚子属角，壬子属商，这就是黄钟的五种声调。大吕也有五种情况：乙丑、丁丑、己丑、辛丑、癸丑，其五音的对应也与此相同。其余各律从寅到亥都是如此。朱熹说：律共有十二个，每个律都以本律作为宫音，从而生出另外四个律。例如以黄钟为宫，那么太簇就是商，姑洗就是角，林钟就是徵，南吕就是羽，这是黄钟这一宫的声音。如果以林钟为宫，那么南吕就是商，应钟就是角，太簇就是徵，姑洗就是羽，这是林钟这一宫的声音。（五音长短的顺序是宫、商、角、徵、羽；五时相生的顺序是宫、徵、商、羽、角。所以黄钟的宫音发出而林钟的徵音响应，大吕的宫音发出而夷则的徵音响应，这是天然的巧妙契合，不需要人为干预，这就是所说的“同声相应”。）
黄钟对应《易经》乾卦的初九爻；向下相生得到林钟，对应坤卦的初六爻。林钟向上相生得到太簇，对应乾卦的九二爻；太簇向下相生得到南吕，对应坤卦的六二爻。南吕向上相生得到姑洗，对应乾卦的九三爻；姑洗向下相生得到应钟，对应坤卦的六三爻。应钟向上相生得到蕤宾，对应乾卦的九四爻；蕤宾向下相生得到大吕，对应坤卦的六四爻。大吕向上相生得到夷则，对应乾卦的九五爻；夷则向下相生得到夹钟，对应坤卦的六五爻。夹钟向上相生得到无射，对应乾卦的上九爻；无射向下相生得到仲吕，对应坤卦的上六爻。如像初九生出初六，是一阳一阴，这称为同位，同位象征夫妻。初六生出九二，是一阴二阳，这称为异位，异位象征母子。这就是所说的“律娶妻（下生）而吕生子（上生）”的道理。
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)."