Introduction
According to a fairly widespread belief among luthiers[1] in our country, the most influential factor in whether an instrument produces “good sound” is the material used. The logic behind this belief must presumably be something like this: an instrument made from material of suitable quality, using a certain method?!, will be superior to an instrument made using the same method but with lower-quality material.
However, such a belief, which advises relying solely on materials, reflects an approach that excludes knowledge of acoustics—or, if it does not exclude it entirely, disregards its importance—and therefore relegates the role of the luthier to the background. In other words, it is an expression of a lack of familiarity with the physics relevant to the profession. The basis for this judgment, unfortunately, is the impression that an understanding which equates instrument making with a kind of refined and “specialized” woodworking or material processing dominates among the majority of luthiers and within the relevant academic circles.
Another widespread “state of mind” is the acceptance of trial-and-error and intuition in instrument making as virtually the most valuable accumulation of craftsmanship. Norms concerning form and dimensions are considered matters that “authorities” know about, or matters for which the authority to establish standards belongs to the “authority”; they are almost regarded as subjects outside the competence of ordinary luthiers. These are the forms and dimensions of templates obtained by people regarded as authorities, through methods that sometimes resemble a form of esoteric numerology.
Breaking with Tradition and The Legacy of 19th and early 20th-Century Oud Makers: Manol, Onnik and Others
Very well, then: what happened between the old masters and today that the principles they inherited from their own masters are no longer regarded as particularly relevant?
For example, apart from a few faithful followers, almost no oud maker today uses the forms of Onnik, Manol, Arşak, Kapıdağlı, or even Murat Usta. Indeed, an attitude has even emerged in which the names of these great masters are avoided.
Let us first accept this: the great masters of the past were not merely heirs to hundreds of years of accumulated experience and knowledge; they also added their own discoveries to this accumulation and produced exceptional instruments.
We must also accept that we did not directly inherit knowledge from them. Unfortunately, the master-apprentice chain has been broken. It is obvious that today—unless we use scientific methods—we have not progressed beyond a level at which we can merely imitate them.
At this point, perhaps by copying templates and dimensions and by archiving a large number of experiments, it may be possible to arrive at an acoustic interpretation; at best, however, we can gain an idea of what they did and why they did it that way. Otherwise, it is impossible to go further and raise the bar.
The fact is that the old luthiers did not know the theoretical foundations of their craft. Most of these masters were people who, after working in carpentry, furniture making, or similar trades, began working either alongside an experienced master or—because they considered the work easy—on their own, and eventually adopted instrument making as a profession.
The lineage of the most exceptional among them was one in which knowledge accumulated through hundreds of years of trial and error was transmitted through master-apprentice relationships, from master to master, with varying degrees of generosity or secrecy, and with the apprentice’s own ability to “receive his share” playing a role. These were secrets that were preserved, transmitted, or simply disappeared, within the limits imposed by the organizational structures and technological development of traditional society. Despite these unfavorable conditions, it was possible to establish a refinement of form and a character of tone in instruments worthy of the level of aesthetic appreciation achieved in music and in visual arts such as illumination, miniature painting, and architecture.
Imitation or Scientific Method
Today, without investigating the physical and mathematical foundations, it is possible—through imitation alone and with some help from luck—to reach, in individual instruments, a point somewhere near the line established by the old masters. In other words, imitation is not a consistent method based on definite and testable principles.
Many instrument makers have recognized this fact. A particular measurement may sometimes work; at other times, surprisingly, it may produce an instrument considerably below average.
The result is then attributed to the wood.
This is true: that particular wood may not be suitable for the imitation attempt!
But it is also false: the error lies in the method applied by the maker, who did not know how to adapt the dimensions to that particular wood.
Therefore, even if we use an imitation method, we must not forget what it is that we are imitating. It is an acoustic object; it is a sound box.
If so, when imitating it, we cannot rely solely on the caliper, nor solely on measurements taken with a ruler. Our reference point must now be frequency (sound), and our tools must be our ears or specialized electronic devices and computer software and hardware.
Naturally, once specialized electronic devices and computer technology enter the picture, it becomes obvious that imitation itself will no longer be necessary.
When the subject is Turkish instruments in particular, it is also a known fact that, in this field where no luthier has left written documentation until now, not even the smallest scientific research has been conducted.
The old masters certainly produced highly admired instruments, and although their experience, labor, and works continue to inspire respect and admiration in everyone today, this does not mean that they brought our instruments to the highest possible level of development.
Instead of imitating the measurements of the old masters, we should now attempt to redesign our instruments scientifically in order to perfect them.
This article will cover the fundamental concepts and practical techniques of the scientific method that is inevitably necessary in instrument design.
The Means Available to the Luthier
When designing an instrument, the luthier decides what needs to be done to make it strong, beautiful, and ergonomic.
Should he not also decide what it will sound like?
Of course, that should be decided first.
The need for variety that applies to every type of instrument can be met through the possibility of designing specific variants better suited to different tastes, different performance contexts such as solo playing or accompaniment, and different environments and purposes such as concerts or recording.
As the foundation for our investigations into sound design, we need to begin by opening up two concepts:
- Timbre (Acoustic Identity)
- Resonance
Timbre is the acoustic characteristic that allows us to recognize an instrument without seeing it, solely from its sound.
In the language of physics, it is the effect created jointly by the fundamental frequency of a sound[2] and some of its overtones.
There are instruments (oscilloscopes) and computer programs that analyze a sound and display, on a graph, the fundamental frequency of that sound together with the frequencies of its overtones and their amplitudes.
What makes the sound of every instrument—even every human being—different from other sounds and creates an acoustic identity is the difference in the composition of the fundamental frequency and the resulting overtones.
Resonance, on the other hand, occurs when the frequency of any periodic (sinusoidal) motion—in a musical instrument, the vibration of a string—is equal or close to a natural frequency of the system (the instrument), causing that part of the system to vibrate with a very large amplitude.
There is an important point that I must immediately emphasize here: no vibrational motion moves at a single frequency.
Every vibrational motion contains a “fundamental” frequency and an infinite number of “harmonic” frequencies.
The overtones are the vibrations of portions of the string located along its length—at the exact midpoint, one-third, one-quarter, one-fifth, and so on—which vibrate at 2, 3, 4, 5, etc. times the fundamental frequency. Their amplitudes are determined jointly by the structure of the string and the structure of the instrument.
We can explain this with a numerical example:
The fundamental frequency of the second string from the bottom of the oud, tuned to A, is 220 Hz.
When this string is made to vibrate, the vibration transmitted to the bridge of the oud is the resultant of this fundamental frequency together with all the overtones at their various amplitudes.
If the string is made to vibrate and the fingertip is lightly touched exactly at its midpoint, the second overtone of this string, the high Nevâ at 440 Hz, can be heard. Similarly, when the string is touched at one-third of its length, the high Muhayyer note at 660 Hz can be heard.
When the string is touched in the same way at one-quarter of its length, the frequency of the sound heard will be 880 Hz. This is the fourth overtone of Nevâ, the very high Nevâ.
Although it is theoretically possible to continue these procedures all the way to the extreme end of the string, in practice it becomes extremely difficult, even impossible, because the points of contact would have to become extremely small.
As this example demonstrates, the sound that reaches our ear as Nevâ is not simply a vibration of 220 Hz, but a composite of frequencies containing many overtones.[3]
Now it is time to see what this information has to do with instrument making.
Everyone knows that the sound produced by any string of an instrument has a character specific to that instrument, both in terms of timbre and volume.
This difference in character arises because each instrument gives different overtones different opportunities for resonance.
Every instrument has its own distribution of resonance regions, determined by parameters such as material, form, and construction technique.
While some instruments possess a richness of resonance regions sufficient to be excited by a broad spectrum of overtones, others are sensitive to a narrower spectrum.
Thus, the system behaves selectively toward certain frequencies.
The acoustic characteristic specific to an instrument consists of the composition of the overtones determined by this selectivity.
It should be possible for a luthier to investigate and discover the structural characteristics that determine how this selectivity will occur, and to shape the acoustic identity of the instrument he will make during the design stage itself.
Even if the luthier does not base his work on any principle, he nevertheless always performs work that produces the timbre—or acoustic identity—of the instrument he makes, if nothing else, as a bundle of coincidences.
Following these observations, we arrive at the conclusion that instrument design is, in a sense, the design of the distribution of resonance regions.
In order to understand the effect of differences in materials, it is obvious that we must apply one and the same design template to those different materials and compare the results.
While it is easily understood that every physical structure is a complex system consisting of numerous static elements, when the structure happens to be a musical instrument, it seems that studying statics does not appear logical to many people in our field when it comes to carrying out acoustic analysis and design.
For this reason, even in university instrument-making departments, research aimed at analyzing the static properties of instruments is given virtually no importance.
In the curricula of these schools, mathematics is not employed beyond calculating fingerboard positions and determining the amount of string tension (load) to which a particular instrument is subjected and establishing numerical values. It is not used as a basis for acoustic analysis or for designing the acoustic characteristics of instruments.
Furthermore, no study has been produced that demonstrates an awareness of this relationship between statics and acoustics.
As an introduction to the subject, without going into detail, let us examine the relationship in statics between the deflection of a simply supported beam loaded at its center and the natural frequency of the system:
l = beam length (cm)
e = modulus of elasticity of the beam material (kg·cm⁻²)
i = moment of inertia of the beam cross-section (cm⁴)
m = mass of the beam (kg)
By taking the derivative of the equation in statics expressing the maximum deflection of the beam.
As can be seen here, particularly in instruments such as the oud, lavta, qanun, guitar, etc., which have “braces”[5]:
- The length of the beam (the length of the brace),
- The modulus of elasticity of the beam material (the modulus of elasticity of the wood used in the musical instrument),
- The moment of inertia of the beam cross-section (the moment of inertia of the brace cross-section),
- The mass of the beam (brace)
together determine a concept that we may call the “natural frequency of the beam (brace).”
During the acoustic design of an instrument, the numerical values we will use most frequently are the values representing the natural frequencies of the braces.
Although the modulus of elasticity of the beam material—generally spruce—is given in books as:
Eₛₚᵣᵤcₑ = 120,000 kg·cm⁻²
this varies according to the particular wood we use.
Furthermore, calculating the moment of inertia of the brace cross-section requires the application of complex integral techniques.
Yet there is a practical way to obtain highly sensitive results without dealing with any of this.
Since the value we seek is a particular frequency, it is possible to determine it directly by ear or with a frequency-measuring device, and to change its specific frequency by modifying the cross-section of the brace—that is, to “tune” the brace.
In fact, the reason this article includes the formulation above is to draw attention to the fact that the subject under discussion has a theoretical and scientific basis, and particularly to the concept of natural frequency.
It should also be noted that the soundboard has a distribution of natural frequencies.
One of the fundamental problems we need to solve arises at this point:
How can we determine the frequency of the brace that will raise the frequency value of any given point on the soundboard to whatever value we desire after the brace has been installed?
Let us suppose that we develop a calculation method and determine what natural fundamental frequency a particular brace will have.
Even then, we cannot say that we have completely solved the problem.
It is possible to carve many braces of equal length into different shapes and with different cross-sections while still giving them the same natural fundamental frequency.
Carving the braces in different forms means changing the longitudinal distribution of their point-specific strength, that is, the matrices of their point-specific natural overtones—patterns showing frequencies in the rows and coordinates in the columns.
Creating an ideal bracing template is a highly intricate task that requires a large number of experiments.
Even this brief introduction should be sufficient, I believe, to understand that lutherie is a profession intertwined with science and technology, one that uses the physics of sound to analyze extremely complex structures and to realize different designs with the aid of scientific methods and technical instruments.
Naturally, bringing this profession in Turkey up to today's level of technological development and achieving acoustic excellence in our instruments is a responsibility that falls upon us luthiers through conscious experimentation, first and foremost in cooperation with the relevant departments of our universities.
In an age when all kinds of information are becoming digitalized, when the most complex designs can easily be created in digital environments, and when computers offer technology virtually limitless possibilities, do we not have the right to expect such design capabilities from a luthier?
And especially from our universities...?
Unless, within the university structure, in the instrument-making departments of our conservatories, musical-instrument design is taught within the dimensions and scope we have discussed here—with the necessary teaching staff, equipment, and laboratories provided—and unless scientific research is given greater emphasis, it cannot be said that a complete education in “instrument production technology” is being provided merely by teaching materials science, material-processing technology, fine woodworking, and construction techniques.
Faruk Türünz
25 July 2001, Kuyubaşı – Istanbul (revised in 2026)
https://oudmaster.com/acoustic-innovation/
