Mujitsu and Tairaku's Shakuhachi BBQ

jaybeemusic wrote:

I'm wondering....when tuning the bore using the 1/4, 1/2 and 3/4 "spot tuning method" such as ken's pdf., does the area past these points affect the note at all?  for example...if you're playing chi... it seems like the area below the 2nd hole down to the root end has no bearing on anything for that note at all...  is this true?
jacques

Hi Jacques,

The Pressure Point method of tuning is a general guide. It shows how shakuhachi generally behave. However, since shakuhachi are not exact, (especially jinashi) there is some wiggle room with the 1/4 and 1/2 points. On different flutes they are sometimes in slightly different areas. The collateral influence on other notes of these adjustments will also vary from flute to flute. For me, the best way to learn about the bore is to go at it and experiment. Add things in places; wet newspaper, beads on string, chopsticks, etc. See what happens. Make connections. Eventually, your hunch becomes keener. A guide alone isn't enough.

jaybeemusic wrote:

also....John Neptune's sheet about "pressure points" and ken's pdf. page don't always match up as to where these 1/4, 1/2, and 3/4 points are.  what might be the reason for this....
jacques

Last time I checked John's sheet about pressure points I thought the points matched up to my pdf. In Nelson's fine tuning page, he starts the pressure point measurement slightly south of the hole rather than at the hole. Again, these are just general guides to get your foot in the door.

jaybeemusic wrote:

and finally..... what happens to the pitch when you remove material....does it go sharp or flat....i'd like to know before i try it.....thanks....

jacques

Let's say we're working on ro. Adding to the halfway point in the bore will sharpen the pitch of ro. Removing will flatten it.

Below is the fine tuning section of my pdf:

Ken

-------------------------------------------------------------

Fine tuning the bore is the main challenge in constructing a quality shakuhachi. It is a combination of mathematics, luck, educated guess, intuition, patience and perseverance.

This process is, essentially, adding and/or preferably removing space along various areas of the bore until all the tones play well. The actual space along the bore that will need to be removed or added will most likely be minute, but nonetheless, critical to the potential sound quality of the instrument.

Each note has corresponding 'critical points' along the bore which can be adjusted to affect tone and tuning. For the low octave notes, these points are found at the 1/2 point between the blowing edge and the open hole of the note being played (1/4 & 3/4 points for second octave), as well as directly under the open hole. If a particular note is not playing well or out of tune, it can be corrected by adding or removing space at one or more of these areas. To check if space needs to be added, fold up a small piece of wet newspaper (approximately 1 1/2" by 1/2") and apply it to the 1/2 point in the bore. Play the flute to check for tone improvement. (A long split bamboo stick with foam rubber tied to the end works well to slide the newspaper to the desired spots.) If it improves the note, the newspaper can be removed and the area can be built up with a dab of glue and sawdust, ji paste, or paste resin. If there is no improvement, try adding newspaper to the other critical points. Then try adding in different combinations, then at every centimeter along the bore. You can also experiment with smaller or larger pieces. If there is no improvement after exhausting all the possibilities, you will need to remove space at one or more of the critical points. Various tools will work to remove space. You can wrap a thin strip of coarse sandpaper around the end of a dowel or weld a 1/2" section of a bastard file to a metal rod. A dremel sanding drum bit on the end of a long rod also works well. If the tone improves after grinding one or more critical areas, stop and move on to the next note that needs improvement. If there is still no improvement or the tone sounds worse, the areas will need to be refilled. It is also possible that a combination of adding and removing will be needed. This is where experience helps. A good rule of thumb is to exhaust every possible simple solution before attempting the complicated combinations. Altering the critical points for one tone can also affect the other notes as well so it is important to work slowly to get a feel of what is happening to the flute on a whole.

It takes patience and experience to develop a mental map of the shakuhachi bore using this fine tuning method. It may be helpful to work a little every day or two to slowly get to know the peculiarities of each flute. Each is unique, requiring an approach which is beyond pure mechanics. The shakuhachi is much more than physics. Listen to the bamboo.

Thanks a lot for the advice.... everyone's been so helpful.  but i've got a few more questions.....

1.  How big/long are these "pressure points"?  are they a specific length?  or are they a percentage of the total flute length?

2.  How much can you alter the pitch?  5 cents?   50 cents?  or a whole semitone?

3. At what point do you decide move the hole location instead of bore work?  or do you do both hole movement and bore work?

4.  Does the bore work change the timbre of the flute or just the pitch of certain notes?

I know i'm asking a lot of quesions but this place is sooo great.

Thanks a million...


btw....thanks Perry for the flute i bought from you last month....it is incredible.....so easy to play....  it shows me just how far i have to go in my shakuhachi making journey.... 


Jacques

Hi everybody.
I have read everything above, it is very helpful. Great thank’s.
I have started new flute (work with non root bamboo), stopped on 1-st hole. It is 6 mm at this moment. It is 50 cents flatter in otsu and 1 semitone flatter in kan than it have to be. If I will enlarge the hole to proper pitch in otsu then difference will reduce. I have stopped to experiment with additions. There is two ways: do addition to sharp note (Tsu) in kan, do addition to flat note in otsu. I have experimented with plasticine bead on string. I tried to affect on note in kan (the diameter of bead was 7 mm) and there was no effect. May be I’d not observed it.
My questions are:
1. How much bead affect on note?
2. How big must be addition(its height) to flat or sharp pitch on 30 cents?
3. If I correctly understand to affect on note in otsu addition have to be near 1 inch length (to 1.8 flute), what if it will be shorter?

Thank’s.