By studying a combination of sources—Buddhist music-theory tomes, part books, and present-day performance practice—one can understand many of the basic principles upon which ancient Japanese music was founded. From what has already been said about the beginnings of Japanese court and religious music, it is not surprising to find that the complete tone system of both types consists of the 12 tones of the Chinese system. The only difference between the Chinese and Japanese tones is the pronunciation of the character for each pitch’s name. Only the Chinese name is given in the illustration below.

Of the four Japanese scales ryo, ritsu, yo, and in, the first two show that ancient Japanese music followed the East Asian tradition in the use of two seven-tone scales, each with a pentatonic core. The ryo scale shows no great difference from the Chinese seven-tone scale. The ritsu scale, however, seems to reveal the early presence of an indigenous Japanese tonal ideal with the placement of its half steps.

Japanese gagaku and Buddhist music theories contain most of the classical Chinese ideas concerning transpositions and modes, but in practice the ryo and ritsu scales could be constructed on only three pitches each: ryo on D (ichikotsu), G (sōjō), and E (taishiki); and ritsu on E (hyōjō), A (ōshiki), and B (banshiki). Note that the pitches for such transpositions form a classic pentatonic (D–E–G–A–B). The two names for the pitch E are present in order to make a distinction between the two scales possible on that same tone. In the unaccompanied court songs and the chants of Buddhism, one can observe the use of other transpositions, for all oral traditions in the world “adjust” notated pitches to the preferences of given singers. In gagaku instrumental music, the six tonalities are observed, part books for each instrument being organized in sections by the tonalities of the compositions. A few pieces, such as Etenraku, are found in more than one tonality. Although set in two ritsu tonalities (hyōjō and banshiki), it is obvious from that example that the piece, which is a “crossover” (watashimono), is more than merely transposed. The pitch centre of the melody also has been changed (from E to C♯). That is one of the few clear examples in performance practice of the mode systems spoken of in music theory. A glance at the related folk song “Kuroda-bushi” and at the in scale provides a preview of an emphasis on such a different mode centuries later.

Vocal music

In the poetry-oriented court life of Japan, secular vocal music would obviously be important. Many of the poems in classical collections seemed originally to have been song texts. One of the oldest secular song forms is saibara, which was first inspired by the singing of packtrain drivers. Among the new fads of Heian period vocal music (called collectively eikyoku) were rōei, songs based on Chinese poems or imitations of them, and imayō, contemporary songs in Japanese. Many gagaku melodies were given texts to become imayō songs, while others were derived from the style of hymns used by Buddhist missionaries. Little of those vocal traditions remains, but memories of their importance are preserved in nearly every novel and diary of the period. For larger surviving repertoires it is necessary to turn to religious music.

Shintō music

The indigenous religion of Japan, Shintō, was closely connected with the legendary legitimacy of the emperor. Thus, special Shintō music was devised for use in imperial shrines. In Japan such Shintō music is called kagura. The kind of music and ritual used exclusively in the imperial palace grounds is called mi-kagura; that in large Shintō shrines, o-kagura; and Shintō music for local shrines, sato-kagura. The suzu bell tree, mentioned before as among the earliest-known Japanese instruments, is found in all such events; and the equally ancient wagon zither can be heard in the palace rituals and sometimes in the larger shrines.

General Shintō chanting (norito) is rather straightforward, whereas the surviving music of mi-kagura is more complex. Male choruses singing in unison (all at the same pitch) are accompanied by the hichiriki double-reed, a kagura-bue flute, the wagon zither, and the periodic rhythmic markings of a pair of long, thin shaku byōshi clappers. The music for mi-kagura ceremonies is divided into two types: one to praise the spirits or seek their aid (torimono), the other to entertain the gods (saibari) in the tradition, mentioned earlier, of the mythological amusements given before the sun goddess. Perhaps the most-famous surviving dance suite from the Shintō tradition is Azuma asobi (The Entertainment of Eastern Japan), which can be seen as a courtly reflection of the agricultural base of Japan in its annual performances during the spring equinox and the summer solstice. The work is said to be an imitation of the dance of a heavenly maiden who performed on the beach of Suruga in the 6th century. Azuma asobi, along with bugaku dances, may be seen at many other imperial, national, and shrine occasions—dim but nevertheless impressive reflections of the colourful courtly life of the Japan of centuries ago.

Mi-kagura is exclusively a male event, but Shintō female dancers (miko) are found in other shrines. Historical documents show that the Heian court, like courts in ancient China or, for that matter, all over the world, appreciated the value of female dancers and their music. In later times the Heian-originated shirabyōshi female dancer-musicians became important elements in the transfer of courtly and religious traditions into later theatrical forms. Although the influence of Shintō music in the Japanese music traditions is evident, the major source of religious musical influence is found elsewhere, in the Buddhist temples.

Buddhist music

There are many forms of Buddhist hymns, such as saimon, as well as semireligious dance songs, such as goeika, nembutsu odori, and the bon odori performed at folk festivals. But the basis of Buddhist classical music, and hence the core of Buddhist influence on Japanese art music, is found in the theory and practice of chanting known generically as shōmyō. Such a tradition came originally from foreign Buddhist missionaries and next from Japanese converts studying in China. Noted sources from the many Japanese interpretations of that tradition are the Shōmyō yojinshu by Tanchi (1163–1237) of the Tendai sect and the Gyosan taikaishu (1496) of the Shingon sect. The theoretical bases of those studies are similar to the ones already discussed under the topic of gagaku.

Here need be added only comments about Buddhist notation systems. Most early chant notations used neumes, squigglelike signs that, like those of the early Christian traditions, served primarily as memory aids with which an initiate could recall the details of a given melody. The most influential system was the so-called go-in hakase, attributed to Kakui (b. 1236) of the Shingon sect. Under that method the five notes of each of three octaves of a pentatonic scale were indicated by the angle of a short line, rather like the hands on a clock. Variations of that method were of great influence in the notation of all vocal music of the period and continue to be used in Buddhist chant today.