The Imperial Register, compiled in twenty volumes in the early eighteenth century by order of Emperor K’ang-hsi (Kangxi), is a guide to 826 basic melodic patterns, and 2306 metrical or tonal variants of the song poem known as tz’u practiced in China since the ninth century. The original Register had no index. The present work supplies this lack, listing each variant title (alphabetically by romanization accompanied by Chinese characters), followed by authors’ names and location in the twenty-volume compendium.