The MIMF - Cumpiano interview

The following was a 2/14/12 interview by the Musical Instrument Maker's Forum with me. The moderator forwarded a number of questions from their forum members. My responses are in italics
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    Moderator: A general comment from one of our members and I’m sure shared by many of us: “Not so much a question ... but as has been mentioned, many of us cut our teeth on his book. And so, if you could forward a big thank-you to him for his efforts in that respect, that would be most appreciated. I think the greatest strength of his book for me was how accessible he made the whole process. You didn't have to go out and buy a bunch of expensive and rare tools, or build complicated jigs, to get started. For first-time builders (and I was one of them), his book was the catalyst. And, I might add, it remains a standard feature in my workshop. I've added many "updates" and personal notes to the margins since. But, it remains my number one reference book.”

1.            Question: Your book has been out for 30 years now and is now in its 15^th or 16^th edition, obviously a very successful endeavor.  Do you have any idea of how many have been sold?  Were you surprised by its acceptance and success?

     My book partner Jon Natelson keeps me informed about ongoing conversations with the publisher, Chronicle Books out of San Francisco. Recently I talked to him and he informed me that-- including the original self-published four editions under the name Rosewood Press and then the eleven or twelve subsequent soft-cover Chronicle Books (they also published, I think it was, two hard-cover editions)-- all added up to something like 85,000 copies sold since the first copies of the first edition became available 1985.

      The book has turned out to a small perpetual-motion machine. Jon and I split a modest royalty, a meager percentage of the wholesale price to begin with, so the remuneration does not add up to a windfall by any means, just about a couple of grand each twice a year. The real payoff—the real profit--has been 25+ years of living under a shower of good will, thanks and admiration from all around the world. In a way, yes, we’ve been surprised by the breadth of its acceptance and its longevity.

      But we could have imagined that any similarly thoughtful and carefully-crafted effort would eventually—even inevitably--be rewarded. What we couldn’t have imagined is that our effort may actually have helped kick-start a Golden Age of American guitar making, as many have insisted to me has been the book’s impact. That is a deeply satisfying outcome, one that we dared not hope for or expect when we started to pen the book in 1984.

2.             You’ve said that the book was a snapshot of yours and Jon’s technique at the time- could you elaborate on that a little? How much is the same, how much is different?

People forget that in the early 80s, when GT&T was composed, there was no such thing as personal computers or word processors. The manuscript of GT&T was originally composed by me and Jon with pencil (yes, pencil!) on pads of ruled paper, then sent to a typist who created a typed final manuscript, which was then sent to a typesetter who created galleys, or strips of typed content in column form, which had to be repeatedly copy edited; which were then cut to length and rubber-cemented onto 250+ page boards; that were then photographed and put onto film; which then was photo-etched on huge rollers to be come published book pages. To make a change, update or addition in the book you had to start from scratch and go through the entire process from square one again.  

     Nowadays everything is digital: if you want to make a change or update to a published book you just add or subtract the text on the original digital file, press a button, and the new updated edition of the book is spit out at the tail end of a huge book publishing machine.

Since there was no GT&T manuscript ever created in digital form, it is thus not possible to easily update the book with what I’ve learned in the past 25+ years. I’d have to write a new book from scratch. So although G T&T remains a useful manual as it is, it is indeed just a snapshot of how we built guitars 25 years ago, without the benefit of new tools and techniques to make life easier—let alone the fact that the supplier’s list still contains several entries that aren’t in business any more. Most notably, I’ve abandoned the pinned mortise and tenon neck joint, which I learned during my early days at the Gurian Workshops during the 70s, a scheme which worked reasonably well in a production environment consisting of 10-15 expert workers, (like the one which molded me) but proved to be difficult and cumbersome for a newbie working in a home basement workshop. In its place, and since creating GT&T, I devised (but don’t make any first-use credit for) an effective, foolproof, dead simple, barrel-bolt neck attachment system. I’ve also streamlined and simplified my bracing system, now use a double-acting truss rod, and refined my entire mental model of how a guitar works—not to speak of a more mature understanding of instrument acoustics, adhesives and wood-processing technology—benefits which I’m teaching my students now, but which my book customers are not currently enjoying.

     But now I will be creating a new, easily-and-infinitely-updatable version of GT&T online on www.guitarmaking.com I’ll tell you more about those plans later on.

3.           Count me in with all those thanking him for his book. It was well worth his and Natelson's efforts. It really does seem to be considered the "bible" of guitar building, though I've been wishing for a new edition in color and either hard cover or spiral bound.  I have 3 questions:

a.      Is he considering a revised edition, and if so, has he heard of David Van Edwards and his lute making courses? In terms of detail, the Van Edwards courses are on par with Guitarmaking Tradition and Technology. The Van Edwards courses are HTML based and work like an offline webpage with hyperlinks at the index page taking you to each lesson. There are of course live links too. The course comes on a CD-ROM with a full-sized plan in a box. It's a neat option for anyone looking to make a how-to book.

Our online GT&T project will do that one better: every procedure of every step will be high-quality video sequences, available on a modestly-priced subscription basis. My long-time shop-partner, the gifted luthier and repair technician Harry Becker and I have commenced to produce a new video series showing, in exhaustive detail, the making of steel string guitar, and more. We project its appearance online by mid-2013, with teasers appearing on www.guitarmaking.com before that.

b.      I would like to know what Jonathan Natelson is up to these days and if they are still in contact with each other. Natelson doesn't seem to have an online presence that I have found. Just wondering if he is still building.

My dear old friend Jon Natelson retired from the craft in the late 1980s to return to the career he originally interrupted to become a guitarmaker many decades ago—the legal profession. He spends his time nowadays crafting the legal framework for large historic restoration projects around the country. He still keeps his hand in the Brazilian rosewood supply trade, now and then traveling to and from Brazil and supplying the dwindling resource on a part-time basis.

4.                I'm interested in the Puerto Rican instruments he makes. Anything he'd like to share regarding the status of that project would be great. My wife is from Puerto Rico, and I'm really interested in the culture.  Also, I plan on making a cuatro, but with contemporary 6 string construction rather than the traditional method of using a large piece of wood and cutting out the body. I wonder what kind of adaptations to the 6 string construction he would make to get the best cuatro sound.

After building commissions and teaching, literally all my available remaining time is spent researching and documenting the musical and musical-craft traditions surrounding the family of native stringed instruments of my birthplace, the Caribbean island of Puerto Rico. For such a small country, its instrumental traditions run very deep and cover an enormous ground—most of it undocumented. Me and four other members of the Puerto Rican Cuatro Project we founded in 1992 have become the world authorities on this esoteric subject. Most of our research is summarized at www.cuatro-pr.org. For those interested in building a modern cuatro, I’ve produced a full-size builder’s plan drawing, which is available for sale at the Cuatro Project online store at that address. I hope to eventually supply builder’s plans for the other members of the Cuatro family: tiple, bordonúa and vihuela in the near future.

     The traditional cuatro-making method is called the enterizo or “whole” method, which essentially involves carving the entire instrument out of a single large block of wood, all except for the soundboard, bridge and fingerboard, which are later added onto the hand-carved body and neck shell. This system is not unique to Puerto Rico, but is the way folk-builders built sringed instruments all over the world since the craft began two thousand years ago. But many modern builders do indeed build cuatros out of flat and curved plates of wood, like guitars and all the other instruments that were product of the 5-century-old European craft guild system. The difference: they had saws with which they could saw the wood into thin sheets—and the early folk-craftsmen did not.

     The difference in sound between the enterizo and the assembled-parts method is subtle: the more massive enterizo shell lending a more strident, focused sound and the assembled-parts method producing a more complex and refined sound. Kind of like the difference between an arch-top vs. a flat-top guitar, but more pronounced. A master of this kind of modern-guitarlike cuatro making is Roberto Rivera of Maryland, www.riverainstruments.com

5.           We've all followed his book and it still seems to be the best one out there that I'm aware of, at least. But it's, what, 30 years old? It seems that some new ideas have developed since then (Taylor style butted neck joints, radius sanding dishes, silicone heat blankets for bending, etc.). I'd be curious to know what he thinks of techniques that have come up in the last couple of decades - which ones he like and dislikes? Maybe some he likes the idea but hasn't personally adopted or tried, etc.

Yes, the book documents how the few guitar hand-craftsmen that existed 30 years ago made guitars. But that sequence still serves us well, those of us who still are trying to build guitars over what amounts to a kitchen table and a minimal tool chest. It would be somewhat pointless to comment here of what I think of what Taylor is doing, since the making of several hundred instruments a day is a totally different endeavor than what I do, or care to do, or teach. Taylor has changed the traditional form of the guitar to fit the requirements of mass production. But Martin and Gibson have been doing that for over a century. What we’re dealing with here now is by definition an anachronistic, not a cutting-edge, production-is-king occupation.

      Fashioning individually-handcrafted musical instruments is essentially cherishing how things once were, in a calmer, more reflective world, and it is what I do. Having said that, I love silicone heat blankets, Stewart-MacDonald time-saving gadgets (like the hand-crank fretwire benders and nut-slot-spacing ruler). But I take care not to change the guitar’s traditional anatomy in order to save a little time. And I’ve always maintained that with traditional stringed instruments, anatomy is destiny. Their sound is directly linked and is a direct product of their anatomy and their form. If you change the instrument’s traditional anatomy or its form, you change its traditional sound. Now some changes will exert a greater of a lesser impact on the sound. If Bob Taylor can build more guitars in less time, or fewer guitars that come back to him like a bad penny—by screwing necks into a larger pocket on the sound box atop the sound hole—the more power to him. This anatomical modification of the traditional form apparently has only a small impact on the traditional acoustics of the guitar. If by chance the massive headblock that allows that pocket did alter the guitars sound in a way that made it peculiar or unfamiliar, Bob would be the first to discard that modification.

     But thankfully in my 45-year guitarmaking career I’ve had but one or two bad pennies, and don’t have to face the daunting prospect of having to make a hundred instruments a day. Thus I have no incentive to change a sequence that dates to the mid-19^th century.

     I became intrigued in the use of carbon fiber during a past stage of my career. It was the result of the opportunity presented when a carbon-fiber tennis racquet production engineer with a love for guitars wandered into my shop and engaged me in conversation. He wanted to bounce a few ideas he had off me: he imagined that a secret link existed between traditional guitars and traditional tennis racquets. Both were optimized wooden structures under constant stress derived from tight strings. In both, acoustic considerations were key to optimum performance. The tennis players among you know a bit about the tennis racquet’s “sweet spot” which must be located in a certain spot on the racquet’s structure. Location of the spot requires knowledge of the vibration modes the racquet takes on when struck by the ball.

     Well, my knowledgeable visitor (Rich Janes, by name) had designed numerous racquets and hob-nobbed with numerous famous athletes. He was deeply steeped in the lore, history and romance of the game, as I was with the game of guitars. He said that tennis racquets had benefitted enormously from a new age of technological improvements in polymer chemistry. But he said that guitars remain stuck in the past and remain as backwards as laminated wooden racquets strung with gut. For one thing, tennis racquet strings dropped not only gut but also nylon strings ages ago, and were using a wide variety of other polymer-based strings, with all the qualities that make musical strings better: more elasticity, more tensile strength, more uniformity. Why not guitars? Rich and I formed a partnership and began to promote Tynex cord as a better classic G-string. But all we did was alert DuPont to the prospect of a market for the material for guitars. They then went over our heads and dealt directly with D’Addario, cutting us out. D’Addario sells Tynex G-strings on their Composite series of classic string sets.

     I had come to view sheets of compression-molded carbon fiber as perfect wood analogs. After all, wood is at its essence, longitudinally aligned carbon fibers in a lignin matrix. Its carbon fiber analog is nothing more than carbon fiber aligned in an epoxy matrix. The essence factor is what stands out: I saw compressed carbon fibre as being wood in its basic, essential form. The difference of course being that wood—besides carbon-based fiber and lignin—is an entire organic complex, staggering in its complexity--besides. Its complexity and variability is what makes it so unpredictable to the builder. Reduced to its essence, it was as if we could design this magically acoustic stuff, optimize the layout and formulation after some trial and error—and then simply duplicate the optimized material by repeating the same formula indefinitely.

     At the time compression molded carbon fibre was enormously expensive to prototype, but Rich had the connections and he produced a 1/16^th sheet of 10 plies, with the plies layered up in a proprietary way which induced induce the same anisotropic characteristics as real wood, i.e. stiffer in one direction and less so in the other.  I made several guitars with the material, with promising results, which we tried to interest Bob Taylor and Chris Martin and the Fender folks in. There was some interest, but they all were toying with the stuff on their own, and ended up pretty much ignoring us. Then we discovered that our patent was being infringed by the Rainsong Guitar company, but we had not the resources to defend it in court. So we abandoned the project. The carbon sheet material was expensive, difficult and problematic to use for individual luthiers, so eventually I put the entire matter behind me. I am still pursuing the idea of a braceless carbon fiber-topped guitar with some people that used to be principles at the Guild guitar factory, but it’s just a gleam in my eye right now. I ended up learning a lot about the material but in the end it proved to be a huge distraction from my own work.

So much for graphite. But indeed, I’m always open to modern gadgets and contrivances, even some of the silly things you find at StewMac, much of which I call “seduction of the innocent.” I always try first to improve my manual skills to do difficult work on my own, before giving in to labor-saving gadgets which usually end up being restrictive in other unsuspected ways. I once figured out a gadget which allowed me to rout the end-graft slot on a completed soundbox. It took two days of fussing with the fixture, half an hour to set it correctly on the guitar and then adjust the depth of cut on the router. Then something slipped and in a nano-second, I ruined the soundbox. But it usually took me twenty minutes to perfectly and safely mortise the end-graft with a x-acto knife, straight edge and sharp chisel. A lesson for the learning: time saving devices are always seductive. Better to use the time developing your own your hand tool manipulation and sharpening skills.

     Nevertheless I am a great fan of some StewMac and LMI time savers: I use their silicone heating blankets more or less exclusively now, as well as their nut-spacing ruler, fretwire radiusing device, and fret-tang clippers. But I consider those radius-sanding shells as useless and unnecessary. Who ever said the top and back plates had to be sections of a sphere? The point of arching the braces is not the attainment of some kind of a spherical dome, but simply to stiffen and strengthen the back plate by imparting a slight curve to it. All the back and top needs to be is...not flat— to succeed in that. The idea that somehow turning it into a section of a sphere makes it “reflect sound” better somehow is borne of pure ignorance of basic acoustics. The only kind of waves that are somehow focused by a reflector are microwaves. And then those are parabolic in shape, not spherical. Acoustic waves are far too slow and large to be effectively reflected by solid objects and so can actually go right through them—like people talking in the next room can be heard with the doors shut. Yes, absorption damps some frequencies and some of the very highest in the range probably get reflected back. But any claims that doing so somehow improves the projection or “goodness” of the guitar should be taken with a high degree of skepticism.

6.           Lots of people on the internet forums learned to build by reading his books and blog. What has he learned from the internet and how has it helped his building?

The internet is bloody, mine-infested battlefield for the inexperienced builder. True, now and then valuable nuggets of enlightenment can be found. But I urge everyone reading this to dismiss out of hand any and all talk that purports to explain how a guitar works or what can simply be done to optimize it’s sound. Assume that NO ONE FULLY KNOWS HOW THE GUITAR WORKS OR WHAT YOU NEED TO DO TO CONSISTENLY ACHIEVE “BEST TONE.” The internet is amply populated with both fakers and fools who with little shame or hesitation will assert claims (of certain knowledge of the guitar’s behavior or schemes that result in consistently improved “tone”) without any proof or evidence whatsoever. So when you come across it, tag it as BS first, unless the claimant’s bonafides can be ascertained first. And even then, retain a measure of skepticism. There is no reference for beauty, as I learned from a fortune-cookie once.

7.           We seem to get regular questions about building cuatros and similar instruments; I understand William has a strong interest in these. Public information on these instruments is sorely lacking. Maybe he could share some of his parts suppliers and construction details. Has he ever thought about a construction book for similar folk instruments?

8.           It would be great to see tutorials on alternate neck-to-body joints and especially V-joints. There is a real shortage of information on early instrument construction in general. William may not be interested in anything like this, or in revising his 30 year old book, but maybe he will put something together on the cuatro and other Puerto Rican instruments. Hopefully he will continue to produce more instructional material amongst all his other endeavors. Not only is he a master builder, but a good teacher. Those two don't always go hand in hand.

         It would be nice to see more on neck to body joints and peg head to neck joints, in addition to laminated neck construction, early guitar building and an inquisition into Spanish Vihuela construction methods ...not that I might need this information for myself.

1      1.  Your most admired luthier?

My eternal mentor and personal career-model has always been Manuel Velazquez, the Puerto Rican senior builder now living in Winter Springs, Florida. He, like my other ideal Gene Clark, are semi-retired now, but during their heyday, they were the world’s greatest living luthiers. The late Manouk Papazian of New York was another giant I greatly admire.

Among builders of the past that I strive to emulate are Mario Macaferri and the turn-of-the-century Santos Hernandez.

Among present day working builders, I take my hat off and humbly bow to Michael Millard of Froggy Bottom Guitars, the classic-builder Alan Chapman, and the Puerto Rican builders Manuel Rodriguez and Miguel Acevedo Flores

1     2.  Any words of wisdom or secrets to pass along to the full-time or hobbyist luthier?

Be very, very skeptical of any and all claims of foolproof, controllable acoustic “adjustment” of guitar tone by scratching little bits of wood in diverse magical, discrete areas of the guitar, whether its called “tap tuning,” “tone adjustment,” “top tuning,” or by any other seductive name. There’s nothing useful there to learn, no matter how “scientific” or enticing or romantic it might seem.

The secret of consistent excellence in guitarmaking lies among the following, if anywhere:

·       Architectural optimization: minimum adequate structure: like Ervin Somogyi once said, “guitars sound best when they are built just beyond the cusp of collapse

·       Precision and control of the guitar’s three-dimensional geometry

·       All tonewoods selected for even, uniform, texture and fiber organization

·       Forget the specie. The most expensive, exotic, and rare hardwoods add not a whit of tonal advantage over inexpensive and plentiful alternatives. Experiment with local materials. One of the great, unknown domestic hardwoods of the future is mid-western Sycamore.

·       Soundboards should be selected for predominance and proliferation of medullar rays (“silk”) over all other factors. This feature reveals the material at the peak of its architectural efficiency (i.e., its stiffness/mass ratio).

Is this why is it called a "nut"????

Nut: from the German nut, (pronounced noot)
"nf. mortise, recess or groove in a piece of wood or another material that fits together with a corresponding projecting piece of material, joint, slot,

Hmm, so the noot is actually the recess at the starting end of the fingerboard where the nut sits into. Just that the actual "projecting piece of material" sitting inside the nut eventually came around to become the nut.

Or maybe it's the string "grooves" or noots in the bone piece sitting in the noot at the starting end of the fingerboard that gave the bone piece the name nut.

All the rest is sound and fury - Part II

Last January I revealed the results of a recent French NCSR double-blind listening test of violins, which placed authentic Stradivariuses and Amati violins in stark competition with less-famous old violins and some new, competently-made violins. The results indicated that a panel of "discriminating" listeners were not only unable to pick out the hallowed, legendary old Italian greats but many of the expert respondents even chose the newer instruments as their favorites from the bunch. This happened after only being able to listen--and not see--the instruments as they were played.

     I'm taking the opportunity here to print two responses that I was privileged to receive, to the revelation from highly-regarded scientist-friends: the first from Tim White, my old acoustician/ guitarmaking partner from the late Journal of Guitar Acoustics and then a response to his response from a past student of mine, the neuroscientist/guitar maker from Netherlands, Pieter Voorn.

Tim responds to the revealing double-blind violin listening test by remarking:

What would put a wooden stake through the heart of this thing would be to make the study really scientific by increasing the population of testers from 17 to a statistically significant size, say at least 50 from my practical experience (no math whiz but having to sound like it from time to time).
       In scientific measuring, there is no such thing as 100% certainty, with the scale of truthiness in evaluating measured results ranging from bullshit to dead-nuts being described in terms of so many "sigmas". For example, in particle physics, a "5-sigma" level of certainty is required to qualify as an actual "discovery" (Ref. section 5.3 of this document) I am mathematically clueless as to how to calculate the sigma level of certainty achievable with 17 perhaps not so random testers, but it can be done. If someone wanted to make real scientific waves in this area, I think it would require first obtaining results that met an appropriate scientific standard of truthiness, expressed as a "p-value" or sigma-level of certainty, then seeking to have the results published in a refereed scientific journal such as JASA (Journal of the Acoustical Society of America). Tom Rossing is still kicking around at Stanford U, if the effort needed a properly qualified mentor.
     I admit to being a bit burned out on the whole instrument tone thing, but the last guitar I built with Michael [Millard of Froggy Bottom Guitars] while still having apprentice mind in mid 1975, before getting lost in acoustics, has a tone that raises goosebumps on those who play it, including me, giving me faith that there is something to this discussion of instrument tone. I gave it to my daughter Hattie, who has a lot of musician friends passing through, and they all have the same reaction. So there is some magic there, and it had nothing to do with studying acoustics. I have never matched it since, and I find the mystery somehow comforting.

Pieter Voorn responded to me:

It came as no surprise to see your blog comments on the Fritz paper about old and new violins. I loved it, your Sound and Fury blog. However, I think that the owners of >$200,000 Martins or million dollar Stradivarii aren’t shaken up in the least by this study. Rational thinking is in no way involved in this process of appreciation. As any self-appreciating marketing expert will tell you: we are selling an emotion, not a product.

I guess the research paper did not do much for settling the issue. Some of the comments on the NPR website are hilarious, but they also prove that belief is way more important than ratio.

I don’t quite agree with Tim White’s comment on the Fritz paper not being scientific because I cannot find anything wrong with the science of the study. True, the sample size is not impressive (21 subjects), but the authors are aware of this and they are careful not to over-interpret their findings. For instance, they focus in the discussion of their data on something called confidence limits. If you would repeatedly draw samples (i.e. groups of violin players) of this size (21) from the population of professional violin players and calculate the confidence limits for each sample, you would find that 95% of the intervals between the limits would contain the true (!) mean. In this case, the limits were 18% - 62% for choosing to take home an old violin after playing. That is a pretty broad range around the observed 38% of subjects inclined to take home an old violin. The authors consider the upper limit of 62% “not high”: that is, even if the true mean, the 100% certainty that Tim White mentions, would be 62%, this, in the authors’ point of view, would be disappointingly low for a population of professional players (and old violin owners!). One may agree or disagree with this conclusion but there is nothing wrong with the science. How high a percentage of musician friends of Tim’s daughter Hattie wanting to take home the White/Millard guitar does it take to call it a magical instrument? Tim says the outcome is 100% - “they all have the same reaction”- and Fritz et al. would agree. Now how about 62% of 21 friends? 

Other than that, I (and judging from their paper Fritz et al. too) agree with Tim White that for a real discovery one would need a much bigger sample size and dramatically improve the confidence interval. But, hey, this is the age of publish or perish and the paper was published in an excellent refereed journal ...

You say you want a revolution?

Lybian guitarist urges his buddies on while they smash the state.

Is there a formula for compensation?

For those of you who are new to this, the compensation is the small increment in length added to the string's scale length to compensate for the slight sharpening that occurs each time you press the string down to fret it. As far as an actual formula that predicts what that increment should be, yes, there is a real formula. The late Daniel Haines, physicist at Bell Labs and later a consultant for the CF Martin Organization, gave me the compensation formula he devised, but I don't use it because it is too cumbersome to use. I find that the same compensation of .15" measured at the centerpoint of the saddle works acceptably well for short and long steel string guitar scales (.10 for nylon string guitars). But if you want to try your hand at following the formula here it is for each string:

Where C, as Dan Haines said, "the amount that the saddle half of the string is longer than the nut half of the string" is the compensation, and it's expressed in inches

H is the string height expressed in inches measured at the 12th fret. Notice that it's squared, suggesting that small changes in the string height result in large changes in the compensation required. That's why your guitar goes out of tune as it settles under tension and the strings rise oh-so-slightly off the fingerboard.

E is the constant that represents Young's modulus, or the modulus of elasticity, of the string core material. Steel is 29,000,000. Nylon is around 290,000: roughly 100 times more elastic (or less stiff) than steel.

A is the cross sectional area of the monofilament string or, on wound strings, its core--measured in square inches. That's why steel string saddles are sloped: the thicker strings want more C. On nylon-string guitars its more complicated: the string thickness doesn't go up as neatly and evenly as they do on steel. And since the variation in the inputs of the strings--given the sum of the other factors--is so slight. So that in practice on nylon the variation in total C is so slight among strings that the classic saddle ordinarily doesn't need to be sloped--although in some cases the classic G-strings in some string sets find their intonation improved by notching them back on the saddle. In many cases that can be avoided by using Tynex Gs--(a denser, thus a thinner G), rather than thick Nylon Gs--which can improve the usually notoriously dull and sour G on many classics. Tynex Gs are found on D'addario Composite sets.

L is the vibrating length of the string expressed in inches. You'd use the scale length in this calculation. It's below the line on the formula, so it impacts the compensation requirement inversely. Hence short scales require greater compensation (i.e. mandolin bridges are usually set back as much as 1/4-inch).

T is the tension of the string--at concert pitch--expressed in pounds. Also, because it's below the line on the equation, the lower the tension, the greater the compensation required. Just watch what happens when you drop your low E string to D for dropped-D tuning. Your existing compensation usually becomes insufficient and the floppy low E string goes sharp as you play up the neck. The precise tension of a string is not so easy to find: In order to calculate T you need another formula, found here:

But in order to satisfy that equation, you have to know the precise mass of the string in grams. Got a gram scale? No? That the most accurate way to plug in this number. But if you don't have a gram scale, the next best thing is to go to here. It's a chart which supplies the tensions of the different strings ....  BUT.... on a 25.5" scale guitar. I guess you can approximate what they are on a 24.9 or a 26-inch scale by setting up a proportion. 

So you see the immense hassle. That's why I just rely on the empirical figure of .15" to the midpoint of a saddle that is slanted 1/8 inch in 3 inches? Works fine for me and my fussiest customers.

What the formula is useful for, is to show how the compensation requirement increases in direct proportion to the string height, the modulus of elasticity of the string core material, and the diameter of the string core--but INVERSELY proportional to the string length and tension. So in the equation everything above the line: string height, elasticity, core thickness increases the C while at the same time, everything below the line, on the divisor: length and tension are acting to reduce the compensation required.

So the resultant compensation amount is the result of that  push-pulling of factors. When they are all accounted for the guitar sounds sweet and heavenly. When they are not all accounted for, the guitar sounds soggy and sour. No big deal, huh?

All the rest is sound and fury

Yesterday I read, with delicious pleasure, a transcription of an NPR news report of a recent double-blind listening test--with "seasoned" musicians as the listeners--of two genuine Strad violins, a genuine Guarnerius violin, and three well- and recently-made modern violins. The researcher was an acoustics physicist from France's National Center for Scientific Research. "Everybody wore dark goggles so they couldn't see which violin was which." "No one knew which instrument was which until after the test. That rules out the kind of bias that might creep in when a musician judges an instrument he or she knows is 300 years old and maybe played by someone like Fritz Kreisler." The link is here.

"…of the 17 players who were asked to choose which were old Italians...seven said they couldn't, seven got it wrong, and only three got it right." Most significantly, "When [one] asked the players which violins they'd like to take home, almost two-thirds chose a violin that turned out to be new. She's found the same in tests with other musical instruments. "I haven't found any consistency whatsoever," she says. "Never. People don't agree. They just like different things."

"In fact, the only statistically obvious trend in the choices was that one of the Stradivarius violins was the least favorite, and one of the modern instruments was slightly favored."

I wonder how the last person who paid $3.5 million for a Strad at auction feels about that. Or, for that matter, $200,000 for a prewar D-45. Must shake them up a bit, no?

The test proved to me that the overheated claims I've been hearing over the last 40 years about the source of Strad's "special sound" being mineralized wood buried in swamps for centuries, the "aging" process, or magic varnish recipes that disappeared forever, are total bull-scheisse. The emperor has no clothes.

The inscrutable mythical primacy of scarce Brazilian rosewood and German Spruce is the guitar-world equivalent of this sentimental, often self-serving, fakery. I can add the speculations about crystallizing resins in 100-year spruce to the steaming pile of fake mumbo jumbo. I suspected all this from the beginning. To quote my mentor in guitar acoustics, Tim White, "if you build it to play in tune and play easily, you'll find someone who'll fall in love with it." But that in itself is asking a lot: What really counts is the the individual maker's acquired intuition, commitment and care.

All the rest is sound and fury, signifying nothing.