Bob Crowley shakuhachi at an improv with Philip Lampe and Robert Manzke
I'd bet that many musicians know how their mood affects their playing and have learned how to control it to some degree. The shakuhachi seems particularly sensitive to mood, and the more I listen to the great players and try to imitate some of the tones and sounds they have recorded, the more I appreciate how mental state affects the quality of the sounds I do manage to pull off. The shakuhachi is sort of a dual-use instrument for music making and also for zen meditation.
A clear mind, relaxed breathing, positive attitude and the elimination of intrusive thoughts and external sounds are apparently the prerequisites that work for me. When I am alone I play briliiantly and when others are around not so well, so confidence is of course a big factor. Having confidence seems to be a mix of conditions, people and instrument and if I have a flute that I know is going to reliably hit that note, even if it doesn't sound as good as the better sounding flute, there's the importance of choice. You can see how musicians often choose their instruments and other tools based on confidence and peer consensus, and quite rightly so, as this is a definite boost in their favor.
I also find it helpful to have a distant view off to some far away hillside, which I am fortunate to have from my home which looks out over hill and dale, but I don't know why that helps.
It's intriguing that these minor external things seem to have such a strong influence on timbre. Tone in the shakuhachi and certain other wind instruments is developed and modulated by embrochure. The connection of the lips to face, the mind to mood and then perhaps facial expression extending to body posture and the subjective thought processes, applies to the meditative clearing of mental clutter and central focus on dimensions of sound.
I have Paul Kastner to thank for turning me on to the shakuhachi. Paul and I went to high school together in Newton, MA, and after college he moved to Japan, went to a Japanese music school where he learned to play the shakuhachi under a master, raised a family, started a woodstove business in Nagano, and returned for a visit with his shakuhachi. Today (or tomorrow - he's in Japan now) is his birthday - Happy Birthday!
Link to a shakuhachi-like device I made from a recorder.
Link to a shakuhachi recording session with Philip Lampe