Ichion Jobutsu: the attainment of enlightenment through perfecting a single tone. The goal is not to experience aesthetic pleasure but to achieve personal and spiritual maturity through the realization of the ultimate tone (tettei-on). For in the single tone of shakuhachi, the whole of nature can be heard whispering its secrets.
The essays of Fuyo Hisamatsu (1790-1845) notes that Fuke shakuhachi is a spiritual exercise of breathing through which a state of freedom from the rational mind is achieved. If the shakuhachi is used as an instrument of spiritual exercise, then aesthetic values are reversed: a fine tone is not the goal of shakuhachi practice. Mere musical pleasantry or technical brillliance in the absence of a concomitant spiritual cultivation is devalued as empty mechanical wizardry. The quest to produce an ultimate tone or the true sound of the bamboo assumes a function similar to that of Zen sitting. When playing the Fuke shakuhachi, the practitioner is to experience a meditative process through the sound, similar to the aims of otodamaho*, by concentrating purely on the sound through spiritual breathing so as to reunify the state of body and mind, subject and object.
Ichion jobutsu is characteristic of Buddhist feeling. The sensitivity is made possible by the Buddhist belief that the sound of instruments is to embody the sound of spiritual enlightment itself. The idea of ichion jobutsu is also rooted in Japanese sensibility. Japanese people listen attentively to the tone of a big bronze gong suspended in a temple. They first enjoy the unique timbre of a single sound and then enjoy the ma, the 'space' created after it. When engaged in this moment, they unconsciously practice the aesthetics of a single sound.
*Otodamaho in Shinto is a method of purifying the body and mind through the esoteric power of sound. Japanese animism since ancient times believes that spiritual power resides in all sounds including natural sounds and spoken words. Otodamaho suggests that spiritual practitioners become engaged in a meditative process through the appreciation and embodiment of natural sounds, situating themselves in nature to become part of the universe.
For nothing is more magical than the spirit of sound. All things in this universe are caused by the spirit of sound. Simply listen to a "sound." Simply listen to a certain sound quietly and calm down. That's all... You do not have to listen to music. Listen to a certain unchangeable sound: the sound of a waterfall, the murmur of a brook, the sound of rain, the sound of waves, anything you like.