Lülü zhengyi houbian 律呂正義後編

(Yuzhi) Lülü zhengyi houbian (御製)律呂正義後編 is a considerably enlarged version of the musical book Lülü zhengyi 律呂正義 from the Kangxi reign-period 康熙 (1662-1722) of the Qing period 清 (1644-1911). In 1746 the Qianlong Emperor 乾隆帝 (r. 1735-1796) ordered to add the themes musical instruments (Yueqi 樂器) and musical composition (Yuezhang 樂章) to the Zhengyi and to rearrange the whole text. The resulting text had a length of 120 juan, in comparison to only 5 juan of text in the Lülü zhengyi.

It is divided into ten chapters in which music at particular occasions (offerings, audiences, banquets, contemplation, entertainment) is played, and how this is done, for instance, which types of music is to be played in which sequence (a kind of "suite") and in which key or mode. The modes were to change in the course of the year, each of the twelve months corresponding to one mode. The book includes instructions to the tunes of airs, dances and highly ceremonial drum performances.

The second part of the book includes illustrated information on musical instruments, the "system of music" from ancient times to the Ming period 明 (1368-1644), musical compositions from ancient times on, an investigation into weights and measures as related to the length measure of pitch pipes, and finally question-and-answer section in which the basic meaning of music is explained.

The compendium is included in the imperial series Siku quanshu 四庫全書 and Qinzaotang siku quanshu huiyao 摛藻堂四庫全書薈要.