Compositional and Morphological Comparison among Three Coeval Violins Made by Giuseppe Guarneri “del Gesù” in 1734

Abstract

In the present work, we had the opportunity to study the coating systems of three different coeval violins, namely “Spagnoletti”, “Stauffer”, and “Principe Doria”, made by Giuseppe Guarneri “del Gesù” in 1734. These three violins were non-invasively investigated by reflection Fourier transform infrared spectroscopy and X-ray fluorescence. These two techniques were combined for the first time with a 3D laser scanner. The analytical campaign enabled the characterization of the materials and their distribution within the stratigraphy, mainly composed of varnish and, when present, of a proteinaceous ground coat. Some restoration materials were also identified, suggesting the application of different maintenance treatments undertaken during their history. The preliminary information about morphological and geometrical differences between the three coeval violins were acquired through the 3D laser scanner in order to observe similarities and differences in the design features among the three violins.

New Insights on the Stradivari “Coristo” Mandolin: A Combined Non-Invasive Spectroscopic Approach

“…Visible light images (f/11 and ISO 100) were obtained using a Softbox LED lamp, while UV-induced fluorescence ones (30 s exposure time, f/11, and ISO 400) were collected by illuminating the samples with two Philips TL-D 36W BBL IPP low-pressure Hg tubes (emission peak at 365 nm). In order to highlight and label areas of interest on the surface of the instrument, the UV Analyzer software, self-developed by the Arvedi Laboratory at the University of Pavia, was used [26][27][28].…”

“…Organosilicon compounds were also revealed on the "San Lorenzo" violin made in 1718 by Stradivari as a residue of a contemporary polishing treatment [11]. The FT-IR spectrum representative of the well-conserved areas of the shell (area C in Figure 2b) exhibits the signals of an oil-resin varnish, likely linseed oil in mixture with a terpenic resin [6,28,31], with typical CH stretching bands at 2920 cm −1 and 2850 cm −1 , CH bending at 1462, 1376, and 1385 cm −1 , and a broad C=O stretch around 1715 cm −1 in the KKT spectrum (Figure 4a) [31,36,37]. The carbonyl band is broadened due to a double contribution from the ester groups (oil) around 1740 cm −1 and the acid groups (resin) around 1715-1690 cm −1 , which broadens with degradation and oxidation [38][39][40].…”

X-ray Imaging and Computed Tomography for the Identification of Geometry and Construction Elements in the Structure of Old Violins

“…The non-invasive structural analysis of historical musical instruments is a fundamental tool for defining restoration and conservation protocols, as well as for the study of ancient manufacturing techniques and acoustic analysis related to this class of cultural objects. The importance and value of typical bowed string instruments, on the other hand, requires a non-destructive approach with strict environmental control, fast acquisition times and high spatial resolution [12][13][14][15][16].…”

“…manufacturing techniques and acoustic analysis related to this class of cultural objects. The importance and value of typical bowed string instruments, on the other hand, requires a non-destructive approach with strict environmental control, fast acquisition times and high spatial resolution [12][13][14][15][16]. Through various non-invasive and non-destructive modern methods and techniques, numerous researchers have performed structural assessments of musical instruments, highlighting the richness of details, characterizing their internal structure, identifying defects, assessing the thickness of structural elements of wood and its density and conducting a dendrochronological investigation of historical violins [16][17][18][19].…”

Signature Modes of Old and New Violins with Symmetric Anatomical Wood Structure

“…Other studies have highlighted the effect of aging wood and varnish, the contribution of the primer and even the attack of fungi on the acoustic quality of old violins [25][26][27][28]. Studies conducted over time on old and new violins show contradictory results: in some studies, the acoustic and dynamic response of old violins is presented as a standard for the analysis of new ones; in other studies in which the acoustic impressions of soloists were analyzed through blind tests (without the respondents seeing the violins or knowing their history), the results showed that, from the point of view of the acoustic criteria, the new violins present a much more appreciated acoustic quality than the old ones [24,[29][30][31][32][33]. The correlations between the signature mode and the modal shapes of the violin body, as well as the connection between the vibrations of the violin plates as individual structures and the plates integrated into the violin body were studied numerically and experimentally by [34][35][36][37][38].…”