Wood Densitometry in 17 th and 18 th Century Dutch, German, Austrian and French Violins, Compared to Classical Cremonese and Modern Violins

Abstract Classical violins produced by makers such as Antonio Stradivari and Guarneri del Gesu have long been considered the epitome of the luthier's art and the expressive tool of choice for the most celebrated violinists. It has been speculated these makers had access to wood that was unique in some way and that this was responsible for their acclaimed tonal characteristics. In an attempt to discern whether the above conjecture is true, we analyzed 17 modern and classical Dutch, German, Austrian and French violins by wood densitometry using computed tomography and correlated these results with our previous study of modern and Cremonese violins; in all studying 30 instruments of the violin family. In order to make this comparison possible we developed methods to cross calibrate results from different CT manufacturers using calibration wood pieces. We found no significant differences in median densities between modern and classical violins, or between classical violins from different origins. These results suggest that it is unlikely classical Cremonese makers had access to wood with significantly different wood density characteristics than that available to contemporaneous or modern makers

Wood Densitometry in 17 th and 18 th Century Dutch, German, Austrian and French Violins, Compared to Classical Cremonese and Modern Violins

Abstract Classical violins produced by makers such as Antonio Stradivari and Guarneri del Gesu have long been considered the epitome of the luthier's art and the expressive tool of choice for the most celebrated violinists. It has been speculated these makers had access to wood that was unique in some way and that this was responsible for their acclaimed tonal characteristics. In an attempt to discern whether the above conjecture is true, we analyzed 17 modern and classical Dutch, German, Austrian and French violins by wood densitometry using computed tomography and correlated these results with our previous study of modern and Cremonese violins; in all studying 30 instruments of the violin family. In order to make this comparison possible we developed methods to cross calibrate results from different CT manufacturers using calibration wood pieces. We found no significant differences in median densities between modern and classical violins, or between classical violins from different origins. These results suggest that it is unlikely classical Cremonese makers had access to wood with significantly different wood density characteristics than that available to contemporaneous or modern makers

A Comparison of Wood Density between Classical Cremonese and Modern Violins

Classical violins created by Cremonese masters, such as Antonio Stradivari and Giuseppe Guarneri Del Gesu, have become the benchmark to which the sound of all violins are compared in terms of their abilities of expressiveness and projection. By general consensus, no luthier since that time has been able to replicate the sound quality of these classical instruments. The vibration and sound radiation characteristics of a violin are determined by an instrument's geometry and the material properties of the wood. New test methods allow the non-destructive examination of one of the key material properties, the wood density, at the growth ring level of detail. The densities of five classical and eight modern violins were compared, using computed tomography and specially developed image-processing software. No significant differences were found between the median densities of the modern and the antique violins, however the density difference between wood grains of early and late growth was significantly smaller in the classical Cremonese violins compared with modern violins, in both the top (Spruce) and back (Maple) plates (p = 0.028 and 0.008, respectively). The mean density differential (SE) of the top plates of the modern and classical violins was 274 (26.6) and 183 (11.7) gram/liter. For the back plates, the values were 128 (2.6) and 115 (2.0) gram/liter. These differences in density differentials may reflect similar changes in stiffness distributions, which could directly impact vibrational efficacy or indirectly modify sound radiation via altered damping characteristics. Either of these mechanisms may help explain the acoustical differences between the classical and modern violins

Density maps of the top (A) and back plates (B).

<p>The contemporary violins are presented on the top row, and the classical Cremonese on the bottom row. The violins have been anonymised. Scales are given in kg/m3. The central violin in the lower row has had more repair work than the other antique violins as evinced by reduced thickness (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002554#pone-0002554-g001" target="_blank">Figure 1</a>.) and increased densities. The dark areas at the centre of the lower third of all violin tops are metal artifacts from the string ends. The dependency of the measured density on plate thickness was eliminated in the quantitative analysis.</p

Thickness maps of the top (A) and back plates (B).

<p>The contemporary violins are presented on the top row, and the antique on the bottom row. The violins have been anonymised. Scales are given in mm. The fourth instrument on the upper row is a viola, which typically is thicker than a violin (image size has been reduced to match that of the violins).</p

Table of instruments studied.

<p>Table of instruments studied.</p

Density differential versus median density of all top and back plates.

<p>Density differential versus median density of all top and back plates.</p

Regions of interest (ROI's) on violin plates.

<p>Five different ROI's of 100×100 pixels were defined, carefully avoiding repair work. The same areas were taken from the top and back plates.</p

Comparison of the median density between modern and antique back and top plates from this study.

<p>Error bars indicate median values and the 95% confidence intervals.</p

Density maps in gram/liter of the back plates.

<p>Density maps in gram/liter of the back plates.</p