Everything about a shakuhachi in terms of dimensions effects the sound and feeling of a shakuhachi. From the volume or size of the bore to the size of the finger-holes and the blowing-edge, mere millimeters of change can have noticeable or even profound effects. If a maker crafts a nobé or “whole” jinashi shakuhachi and leaves the inside mostly natural, then nature determines most of the sound and feel. By contrast, a jiari maker fully shapes the inside using paste and adjust the length via a center joint so in effect they’re shaping most of the sound and feeling. Finger-hole placement and dimension determine a good portion of the sound and feeling. The dimensions of the blowing-edge or “utaguchi” plays a huge role in the overall sound and feeling with mere millimeters of change to this area having a profound effects.
The following is me answering an email from a student and friend about the sound and feeling of shakuhachi.
“Now, what I don’t know about since I’m really not that good yet is do all shakuhachi have the same potential? Is it all based on the player and not the shakuhachi, in the end?”
All well made shakuhachi have a lot of potential but it depends on the player to bring it out. When comparing well balanced shakuhachi what sticks out to me the most is the feeling or how they respond. More narrow bore shakuhachi require less power for a loud sound while wider bore shakuhachi take more power to achieve the same volume but are often quieter and darker. Wider bore shakuhachi can often take blasts of air and one gets the sense they can play a bit more wildly and unrestrained. Narrow bore shakuhachi can also take blasts of air but generally one has to be a bit more careful so as to not over-load them which results in high pitched squeaking or shrill octave jumps.
Both are good for different situations, approaches, or levels of ability. I like to play with a lot of power as well as gently or dynamically, and since most shakuhachi can be played gently with favorable results, I tend to prefer wider bored shakuhachi because I don’t have to hold anything back. It can feel nice to really put in near maximum effort, even if you could get a louder sound for less effort on a more narrow bored shakuhachi. A beginner would find a narrow shakuhachi easier for certain and thus more favorable in most cases.
“Is it just a matter of finding or learning how to play each one [instrument] individually?”
Essentially yes, though well made balanced shakuhachi of any variety should respond to the same methods or techniques from the player to produce certain desirable sounds. Mostly full ringing sounds when pushed into more harmonics or overtones. If a shakuhachi can’t be pushed into these overtones on key notes than physically these shakuhachi are out of balance with themselves.
With old jinashi one often experiences unbalance on the fundamental note or RO. Often Otsu and Kan will be out of balance with one outshining the other in terms of range or stability when pushed. Almost all shakuhachi benefit from being balanced with careful work in the bore via subtractions and or additions.