I have been intruiged with sound and full tone of instruments; what to do to play its best to my ears. With a recorder, the instrument I started on, there was little to no room for changing or influencing the tone itself. Then I played saxophone: a whole lot more room for change! Soft, loud, roaring, sharp, fat etcetera. It was not really hard to make the sound, sound good and fat: relax your jaw and blow with a concentration\ steady pressure. On the shakuhachi is is harder to grasp. There is just as much room to change the tone, maybe even to a larger degree than the sax. But making a flute 'sing' is another thing. I sometimes have that sensation. Mostly after playing a more difficult part when I played more tensed then usual. After that I relax and doodle around on the flute, it sounds very nice! Then it really sing, it feels as a focused relaxed way of playing, which 'unlocks' this sound. I can't do it on demand -yet- though, which will come perhaps. When it comes now it feels as a little gift and gives a glimps of the most beautifull aspect of the shakuhachi: its complex sound.