Kangen and Bugaku pieces are classified into two groups: Sahō (music of the left) and Uhō (music of the right). Music of the left consists mainly of music from China and several pieces originating in India, while the music of the right consists mainly of pieces from Korea and a few from Manchuria.
In terms of the instrumentation, the sō (a zither or harp-like instrument) and biwa (a four-stringed lute) are used only in Kangen music of the left. The flute and side drum differ between the Left and the Right. The basic shō (mouth organ) is not used in the music of the right.
Performance
A short explanation of the characteristic orchestral structure of Kangen should be added here. The hichiriki (oboe) plays the main line of melody, while the ryuteki (flute) melody parallels it, obbligato style. The lowest note of each chord on the shō follows the key notes of the main melody. This means that the chords hang over the melody, which is the reverse of modern Western music (monody) in which the melodic element is supported by the chord. The highest note of each chord played on the biwa and sō, however, follow the key notes of the melody, in a supporting role similar to what you find in monody. Kangen is the only known music in the world which has a harmonic structure where the melody is supported by harmony both from above and below.
Kangen and Bugaku are based on a tone system borrowed from the Chinese system of the T’ang dynasty. It consists of twelve tones (chromatic scale), two seven-tone scales, called ryō and ritsu, and six tonalities called rokuchoshi. The first three examples are in the ryō scale, while the remaining three are in the ritsu scale. The keys vary except for taishikicho and hyōjō, which are in the same key, E. Some of the names of these six tonalities are derived from the name of the note of the key. The names of the twelve tones are shown in Notation 1. Kangen and Bugaku compositions can be classified into three genres according to the size —small, medium, and large.
The largest pieces consist of three movements, called jo, ha and kyū, which can be translated roughly as (slow) introduction, (breaking) development, and (rushing) conclusion. The tempo is generally very slow and the difference between slow and fast does not vary to the same extent as modern Western music.
The smallest piece consists of one movement, the parts of which are usually repeated in da capo style. Performance of a piece or movement usually begins with a flute solo which is followed by a tutti at a certain given point.
Before the performance of a piece, as a rule, a short section of the tonality to be used is played. This is a stylized manner of tuning the instruments based on the fixed pitch of the shō. It also serves as a warm-up for the performer in the true atmosphere of the performance to follow.
Another noteworthy performance style is a kind of freestyle canon. It can be heard in the jo movement of Bugaku dances of the left. The chief shō player starts playing the melody, followed by the second shō player several beats behind, then the third shō player. The chief hichiriki player then joins in with the shō ensemble, then the second hichiriki player, and so on. The flutists join the ensemble in the same fashion. Thus the entire ensemble of three different wind instruments forms a free-style canon in free rhythm creating a charmingly chaotic sound coupled with a marvellous dynamism.
The same performance style is found in six pieces, called Choshi (one piece for each tonality). Choshi is used for the entrance of dancers (dancers of the left wear red, while those on the right wear green). The number of dancers varies according to the piece—one, two, four, six and sometimes eight. Pieces performed by one dancer are rather special. In Bugaku dance of the left such pieces almost all originated in India, and the costumes for the dancers are also unusual, representing the survival of a non-Chinese origin.
In Gagaku concerts, besides Kangen pieces, songs called Saibara and Rōei are also often performed. Saibara literally means pack-horse driver songs. It comprises songs composed in the Heian period, based upon contemporary folk songs but artistically modified to make them more palatable to the court. The existing repertoire of six pieces was restored in the late 19th and early 20th centuries. The songs are accompanied by ryūteki, hichiriki, shō, biwa, and sō, while the leading singer beats time with a wooden clapper called a shakubyōshi. The shō plays the melody instead of harmony.
Rōei, literally meaning chanting, is another type of song, the texts of which are taken from two collections of Chinese and Japanese poetry (Wakan Rōei Shū and Shinsen Rōei Shū). Rōei had also once fallen out of use and the current fourteen pieces were restored in the modern period. The songs are accompanied by one ryūteki, one hichiriki, and one shō. The shō plays the melody.
This genre of Gagaku differs completely from the former three genres. It has its origin in ancient indigenous music, and is used for ritual ceremonies of Shintoism at the Court and some shrines. The singing style as well as the instrumentation is also specific. The present-day performance style was established in the early Heian period, when styles of Kangen, Bugaku, Saibara, and Rōei were also established. Slight influences can be traced from Kangen, Bugaku, and Saibara in this ritual music, for instance, in the use of the hichiriki.
There are four major pieces of this genre: Kagura, Yamato-mai, Kume-mai, and Azuma-asobi. Kagura forms the largest portion of the genre. The term Kagura literally means “music of the gods.” It is nowadays used also for folk ritual music at shrines, small and large, all over Japan. This folk Kagura is often called Sato-kagura (country Kagura) or Okagura, while the Kagura in the court is named Mi-kagura.
Mi-kagura is performed in the Court shrine with the attendance of the Emperor on the 15th of December and in certain other cases of ritual ceremony. The complete ceremony used to take several days to perform, since many of the pieces were accompanied by dance. Now, however, the ceremony is abbreviated to around six hours in the evening.
The ensemble to accompany the pieces consists of three instruments, kagurabue (flute), hichiriki, and wagon (zither), plus two shakubyōshi (clappers), played by the leading singer from the two choruses.
The kagurabue is a transverse bamboo flute with six finger holes, producing a (closed) D, E, F, G, A, and C. The hichiriki is the same as previously mentioned. The wagon or Yamatogoto, literally meaning Japanese zither, is a six-stringed zither, 192cm in length. Its silk strings are tuned by six bridges made of natural wood. The strings are played with a thin plectrum shaped like a spatula.
Yamato-mai is a short piece performed by four or six dancers dressed in the ancient costumes of civil bureaucrats. The ensemble consists of kagurabue, hichiriki, wagon, and chorus. The chorus leader marks the beat with a shakubyōshi.
Kume-mai literally means dance of the Kume (a clan of ancient warriors). The dance is a short piece performed by four dancers dressed in the ancient costumes of court warriors. It is accompanied by an ensemble of kagurabue, hichiriki, wagon, and chorus.
Azuma-asobi, literally play of the east country, is a dance piece performed by either four or six dancers dressed in the costumes of court warriors of the Middle Ages. It is accompanied by the same ensemble as above. The song consists of four shorter pieces, the first and second of which have no dance. In the dance, as well as in the Kume-mai, instrumental music is played for the entrance and exit of the dancers.