This article is a study of the musical notation of the shomyo of Horyuji temple, dealing firstly with an introduction to a number of historically important collections of notation, and secondly, using that material to undertake an historical study of the notation itself. In the opening section of the article, collections of notation used in the Horyuji kekae service have been classified. (The kekaee service, held in early spring, is one of repentance and supplication. At the present, three kinds of kekae service are celebrated: the Kichijo keka, which has as its main image of worship the goddess Kichijo or Srimahadevi; the Kannon kekae, with the main image Kannon or Avalokitêsvara, the Goddess of Mercy; and the Yakushi kekae, with the main image Yakushi or Bhêchadjaguru, the Physician of Souls.) In the second section of the article, a group of six manuscripts and associated source material dealing with the shoryoe, a service which commemorates the anniversary of the death of Shotoku Taishi (574-622, son of the female Emperor Suiko and founder of Horyuji temple), have been classified and their contents collated. The six manuscripts in question are:
A. Shoryoe shomyo-shu (Kondo-bon), a shahon (hand-written manuscript) presently held in Horyuji temple, estimated to have been written in the Kamakura period (13th-14th century). The manuscript was found underneath the roof of the kondo (main building) of Horyuji temple during repairs undertaken in the 1940s, and has been identified recently by the Horyuji monk Takada Ryoshin as a collection of shomyo notation for the shoryoe service.
B. Shoryoe shomyo-shu, a shahon held in the Research Archives for Japanese Music, Ueno Gakuen College, Tokyo, estimated to have been written in the Nambokucho period (late 14th-early 15th century). This manuscript appears to have been owned by the Horyuji monk Joyo (1487-1546), who reached a position in the hierarchy of the temple second only to the head of the temple, since it includes his signature. It can be inferred from this that the manuscript was written before Joyo possessed it.
C. Hossoshu sanji kaju, a printed collection of notation of Meiji 37th year (1904), published by the Hossoshu Kangakuin (seminary of the Hosso sect).
D. The notation used at present in shahon form.
E. The same in its printed form.
F. The notation used at present at Yakushiji temple (also in Nara, and until 1950 of the same sect and branch of Buddhism as Horyuji temple).
The collation and comparison of the contents of the above six items has been largely abbreviated because of space limitations. However, the following conclusions have emerged from this study. The systems of notation used in sources A, B and C resemble each other closely. It is hence possible to state that there were no large-scale changes in the notation system from the Kamakura period until the Meiji period. However, at some point after the publication of the 1904 source, the notation system was thoroughly revised, resulting in the development of the notation system used in sources D, E and F. One aspect of this revision is illustrated by the standardization of direction of the notation —in the modern scores notation for pieces in the Shika hoyo service (generally-used service including the bai, sange, bonnon and shakujo pieces) is all written on the right-hand side of the written characters of the text, whereas notation for those pieces called kada unique to the ceremony commemorating the death of Shotoku Taishi is all written on the left-hand side of the text. Included in this section of the article is a chart illustrating the correspondence between notational symbols of the old and new notational systems.
Although it was not possible to distinguish any relationship between the modern Horyuji notation system a