Japanese timbre NE-IRO and SHIBATA's theory of skeletal system

The cornerstone for SHIBATA's style change was timbre of Japanese instruments and voice. In 1969, SHIBATA researched the Japanese folklore in Okinoshima and was certained himself that the microtonal pitch changes functioned as a timbre in Japanese traditional music. He also explored the unique theory of two-kernel skeletal system of KOTO tuning, which is based on the two sets of pentatonic scale and which is decisive, according to SHIBATA, to NE-IRO of KOTO.

In the prize winning piece Oiwake-bushi-ko the harmony is made incidentally as a result of simultaneous singing of different folkloric melodies. In order to make Japanese timbre of voices, some verbal instructions are written on the score.

As for KOTO tuning system, SHIBATA explained with the example of ROKUDAN. In a traditional music titled ROKUDAN 六段, SHIBATA found two layers(lower and upper) in the monophonic melody, even though Fumio Koizumi thought it was one monody line. SHIBATA indicated two-note sound of B-C in (figure 2.1)belonged to the different group from that of linear progression of B-A in the point of the register and the timbre. Here SHIBATA regarded the register change as the change of timbre as NE-IRO.

Another point of Japanese timbre as pitch change is OSAE one of the method of playing KOTO. OSAE makes the pitch higher, but the upper pitch doesn't function as the pitch itself but should be heard as the nuances or change of timbre, like a resonance in live-electronics including both pitch and amplitude changes.

Figure 2.1: Rokudan and OSAE

So SHIBATA realizes Japanese tone color, that is NE-IRO, of KOTO is keenly connected to register or pitch changes. NE-IRO can't be notated on the usual score, but SHIBATA cited Kiyosa Kanetsune 兼恒清佐 (1885-1997) to show how the Japanese quality of timbre was related to the microtonal pitch changes and how Japanese folk culture included noise as micro tone.

Concerning the Skeletal system and the pitch changes as timbre nuances applied to Oiwake-bushi-ko, SHIBATA explained with his terms Konsonanz and Distanz. Konsonanz is a consonant relation exclusively among the two notes, which in Japanese folklore is the interval of the fourth. Distanz is a pitch distance from Konsonanz. Distanz as pitch distance is also an unstable pitch relation compared to Konsonanz. The relationship between the stable tones and the unstable tones were applied to SHIBATA's live-electronic music in 1970's.