Let's face it, the shakuhachi is an acoustical kludge.

'W' waves of the notes of the first two octaves.

Benade writes:
Mathematical analysis tells us that the frequency of the lowest vibrational mode is determined jointly by the shape and volume of the cavity, while the frequency ratios of the various registers to the lowest are determined by the shape alone. A great deal of time has been wasted by instrument makers and laboratory workers in musical acoustics who are either ignorant of this theorem, or are unappreciative of its importance. We base our understanding of all wind instruments on this point.

What we'll do is narrow the first 1/4 of the flute's length by flattening the pipe's circular shape into a gradual oval terminating at the utaguchi. And to do that we'll create a special tool for a Schedule 40 C flute.

Heat the end of the PVC pipe with a heat gun, insert the tool to the red dotted line, let cool, tap out with a dowel from other end, finish the utaguchi and drill the holes. That's all there is to it! The registers of your flute should now play in balance.

Clear PVC (above) will milk up a little while hot but clears on cooling.

The biggest problem with the shakuhachi is that its acoustical concerns haven't been understood and separated out such that they can be addressed in a straightforward manner. Timbre, tuning, note balance, volume, cut-off frequency, octave balance, hole lattice effects, etc.--all can be addressed somewhat individually with flute designs which necessarily deviate from the standard. And that, Grasshopper, is the rub.

For a page on bamboo jinashi flute design.

Better sounding/playing flutes can be achieved in the following ways:

1) Proper placement/size of holes using the Deaver method

2) Using a cylindrical tube with uniform wall thickness.
For experimental purposes and for 'proof of concept' I've used Schedules 40 & 80 PVC, however, many other possibilities exist.

3) Improve the mouthpiece

4) Adopt less expensive, more durable/available materials
Gray and white PVC is available at most hardware stores. There is also Clear PVC and 6061 Aluminium available in Schedule 40--both for under $2/foot. Phenolic tubes are a promising possibility. Watazumi made shaks of PVC and paper tubes (among other things), so the door is open to many different materials.

5) Achieve octave balance in a straightforward simple manner (see above)

Using the perturbation and mouthpiece specified above, a C flute (262hz) out of Schedule 40 3/4" pipe will be 606mm long. The wall thickness is 3mm as opposed to a bamboo wall thickness of maybe 6-9mm. For our holes to have a similar effective size they need to be smaller than those generally used on bamboo. For those interested in raising the cut-off frequency of their flute, thin-walled PVC is a good choice because large holes and thin walls create a larger effective hole size than can be obtained with large holes on bamboo with it's thick walls.

The Deaver Point is located at 295mm. 9.5mm holes should create near optimal timbre--use 9.1mm for a slightly darker, mellower flute and 9.9mm for a slightly brighter one. Roughly speaking, a 10% change in hole diameter, or a 1% positional change relative to the (acoustical) top of the tube, causes a frequency shift of 10 cents.

Synthesis Flute
Aspect Ratio--29.45 ** EAR--28.94
Measure (millimeters) from top of flute

Hole	9.1 mm 23/64"	9.5 mm 3/8"	9.9 mm 25/64"	General Percentage
5	257	258	260	0.4258
4	293	295	297	0.4868
3	363	364	366	0.6013
2	415	416	418	0.6870
1	473	475	476	0.7833
Ro	606	606	606	1.0000

After you've set up and made a couple flutes
you'll be able to make and finish a flute in a leisurely hour.
Files, twist drills and Dremel burrs for the utaguchi are suitable tools.

Soften (chamfer) edges where air flows (holes, mouthpiece, foot opening)
then rub with Acetone on a paper towel to remove the printing, clean and finish.
Attention to these edges will make a noticible acoustical difference.

To make flutes of other lengths, locate the holes using the GENERAL PERCENTAGES in the table above. Drill small and then, starting from the bottom, increase hole size until each note comes into tune. The PERCENTAGES are optimized for cylindrical pipe but should be suitable for irregular bamboo and other bore sizes as well.

Mark Sheperd has come up with a clever device to quickly lay out the holes of a 'percentage' flute. He stretches out elastic and marks the percentage locations on the elastic. Then it can used to locate the holes of any length flute.

Embarrassed by the look of PVC?

SEM Vinyl Dye does a good job and comes in a variety of colors. Firethorn Red, perhaps? Another look at various automotive vinyl dye colors. You can get a Vinyl/Fabric Dye in spray cans at AutoZone.

But a more interesting approach is to use Rit dye--you know, the original Tie-Dye stuff that you get at the Super Market. Mix about half and half liquid Rit dye and water, immerse the flute(s) inside a metal pipe and bring the temperature up to near boiling--you want it hot. The dye doesn't take in a uniform manner--something about the micro-surface I suppose. Anyway, you'll get subtle (see Wabi-Sabi below) variegations. Make some tests with PVC scrap and a pan on your stove top. Rit color chart PVC comes out of the Rit dye bath with a flat finish. Slap on some furniture wax or Deft Clear Wood Finish (it also comes in spray cans) and you've got a winner.

Krylon now has a new fusion spraypaint for plastic! The stuff is pretty tough.

* Bonds to Plastic
* No Sanding or Priming
* Dries in 15 Minutes or Less
* Features the EZ Touch Fan™ Spray Nozzle
* Available in 16 Colors

The obvious answer to pipe color is to have it custom extruded with a specified internal diameter and colorant dispersed throughout the RPVC matrix. That's what we've done and are now offering custom built flutes.

Another Urban Myth perpetuated by the North American shakuhachi community is that PVC is toxic, that dioxin is released should it burn, that PVC dust will lodge permanently in your lungs and so on. MSDS (Material Safety Data Sheets) for PVC don't support any of these fears.

Embarrassed by the fact of PVC?
Asked another way: Does PVC have Buddha nature?

Urushi lacquer (for the bore) is highly toxic (considered a biohazard in shipping), the red colorant (cinnabar) is a mercury based compound and yellow is an arsenic compound. Madake bamboo groves suitable for traditional shakuhachi are disappearing at an alarming rate. The shakuhachi seems to attract those with heightened environmental sensitivities and quite how they overlook these facts is a little strange.

Bamboo cracks and serious players make an obsession out of attending to the moisture needs of their finicky flutes. Some makers try to get around this defect by placing string bindings from head to foot. Then what's the point of using bamboo in the first place if what you're mostly looking at the 'patches' employed to overcome bamboo's defects? The mere existence of binding should tell you something.

Bamboo for shakuhachi, once an common material, is now scarce and expensive. That it is then encased with lacquer and oils, that a durable material is needed for the utaguchi edge tells you that bamboo's inherent properties aren't up to flute requirements. Throughout the shakuhachi other materials and techniques have been pressed into service to overcome the fact that bamboo is a poor material choice for flutes. The humble bamboo flute took on unnecessary levels of complexity in the form moisture-proof lacquer and oils, inset buffalo horn, various bindings, etc. and become the shakuhachi. And all of these were adopted to circumvent the simple fact that bamboo isn't suitable for flutes.

And then there is the problem of mold growing in bamboo bores, feeding on bamboo starch.

Over time, the shak became a design kludge--endearing, but a kludge never-the-less. The idea of unpretentious elegance is lost beneath an overlay of various 'fixes'. Much of the time, energy, and cost that goes into building a shak goes into these 'fixes' rather than the fundamental instrument. Why should there be an occupation such as Shakuhachi Repair? A material which is waterproof, crackproof and has the integrity to maintain an edge should be a minimum beginning requirement. A basic flute consists of an edge, a resonator and some holes--anything more is extra.

Among a sizable portion of advocates, the 'Zen' aspects of playing seem to amount more to a decision about lifestyle than economy, efficiency and simplicity. A resurgence of the ethic of the original Komuso has yet to take hold. The concept of simple tools and simple methods being strenuously applied is overridden by the current fixation with suizen fashion.

To find out where you fit in all this ask yourself, "Does Suizen serve me or do I serve Suizen? Just why am I wearing this literal/figurative basket on my head?" Can worthwhile principles of Suizen be separated from the cultural background from which it arose? Or do shakuhachi and their accoutrements remain fetish objects to fascinate oneself in the remembrance of and identification with a different time and place?

Get the whole outfit at Mejiro

The previous 38 pages and this Synthesis has been the result of 2 years of thinking and experimentation done in the evenings for relaxation and to satisfy my curiosity. This information is intended to serve as a suitable base for those wishing to make and play their own flutes.

All thirty nine pages are presented in the order in which they were developed and written, so they reflect the directions my understanding took as it deepened. At the onset this project was two-fold: 1) to understand the acoustics of end-blown flutes and the shakuhachi in particular and 2) to design a general purpose utility flute which was simple to make, easy to own, and had superior acoustical qualities--a true Zen flute as it were. I wanted something which exemplified the abundant spirit of resilience.

Each note on a shak has a different tone color (timbre) from the others. This wasn't a design decision, it's a consequence of the bore. So the Japanese turned around and made use of this imbalance to give the music additional 'character'--making the best of a bad situation. But this opens up an interesting area--designing for even greater individual note character. In terms of the flute design I'm proposing on this page, designing for and developing tonal 'character' is a much more straightforward and simple proposition. So we're talking about wabi-sabi sound (yet another wabi sabi book). From a Western point-of-view, we're talking about sound degradation. A first and most obvious approach is to abandon the concept of identical hole sizes. Beyond that, you're limited only by your imagination, creativity and spirit of discovery. Some people seem to have a natural intuition for this kind of thing, some don't.

The first evening Zen master Momataki arrived at Rain Mountain Monastery the monks requested their new master show them the way. When Momataki assented with a nod and pointed to the rising moon all but two of the assembled looked at his finger.

At some point the shakuhachi will come to terms with it's inherent limitations in design and construction methods/materials. Since the Sixties makers have universally begun to pay attention to tuning standards. In the last decade new construction methods and materials have been pioneered by Monty Levenson to good reception. Interest in end-blown flutes seems to be growing world-wide. The shakuhachi may be at the beginning of a revolutionary period of evolution.

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