Lülü chengshu 律呂成書 "The complete book on the pitch pipes" is a book on the musical pitch pipes written during the Yuan period 元 (1279-1368) by Liu Jin 劉瑾. The book of 2 juan length was finished about 1340. It is a very rare text on the tempering of the musical scales with a very special method.
It operates with a concept of cosmology by bringing the twelve individual pipes in relation to the "temporary climate" (hou 候, actually five-day periods) and the "air movements" (qi 氣) during the twenty-four solar terms (jieqi 節氣, see calendar). The twelve pitch pipes are placed in a sealed room and arranged in a circle reaching clockwise from the lowest to the highest tone. Inside each tube the ash of the membrane of reed stems (jiafu 葭莩) or of bamboo is filled. During each of the solar-terms the ash of one related pipe will be blown up by the movements of the air. The amount of ash blown out and scattered around determines if the pipes are rightly tuned (zhengsheng 正聲 "correct tone") or not. This method shows that according to correlative thinking music was directly connected with the calendar.
The oldest texts about the creation of the pitch pipes, Guanzi 管子 (chapter Diyuan 地圓) and Lüshi chunqiu 呂氏春秋 (chapter Guyue 古樂), narrate how Ling Lun 伶倫 created the Yellow Bell Pipe (huangzhong 黃鍾), and on the base of its size, calculated the dimensions of a whole set of twelve bamboo pipes. The calculation was made with the help of the number of millet grains filled into the tube, determining the volume, as well as the length, diameter and circumference of the pipes. There is no talk of the influence of the "seasonal climate" in these texts.
The first text mentioning of the "seasonal climate method" (houqi 候氣) is to be found in the book Xu Hanshu 續漢書 (see Houhanshu 後漢書) by Sima Biao 司馬彪 (d. 306), and it seems that it was invented by the Han-period 漢 (206 BCE-220 CE) Confucian master Jing Fang 京房 (77-37 BCE), but there is no concrete explanation of this method, except in the chapter on calendar and pitch pipes (Lüli zhi 律曆志) in the official dynastic history Houhanshu.
The history book Jinshu 晉書 talks of Xin Dufang 信都芳 from the Later Qi period 後齊 (Northern Qi 北齊, 550-577, see his biography in the history Beishi 北史) who was able to establish a relation between individual pipes of the whole pitch pipe set and the seasons and climate, with the help of the ash method. Du Xinfang is also mentioned in Liu Xun's 劉壎 (1240-1319) book Yinju tongyi 隱居通議 from the Yuan period, where it is said that he was able to "determine the air currents of the seasons with the help of pipes" (neng yi guan hou qi 能以管候氣).
Liu Jin's book combines these ancient methods with the teachings of Song period 宋 (960-1279) Neo-Confucian masters like Cai Yuanding 蔡元定 (1135-1198), author of the Lülü xinshu 律呂新書. The Lülü chengshu is included in the series Mohai jinhu 墨海金壺 and Congshu jicheng chubian 叢書集成初編.