Above all, the final result is the standard while we are assuming the value of a resonant wood, supposing a correct acoustic construction 
method, therefore a certain trend is needed for the selection process in practice. The top wood, which is primarily made from spruce or Norway spruce (abies excelsa), occasionally from silver fir (abies Alba) or from a European silver fir (abies pectinata) should preferably have gently shaped, straight running grains which should neither be too close to nor too rare from each other, and they have to be a bit denser in the middle than towards the edges. The wood – if it was split, – should have a shiny light and a quite light specific gravity. The older German violin makers usually preferred wood with too dense grains. The Amaties chose wood with more rare grains, Stradivari preferred the dense one in his early years, however, later he chose wood with the most beautiful grains.
Savart recommended making a normal stick with defined size from a well-sounding wood, then an identical one from another wood. Savart thought that the quality of the wood could be specified by its own pitch. I find this method too primitive because during this test they did not take the stiffness and the weight of the wood into account, but only its side-tone. The slightly higher-sounding wood – in spite of my opinion – would be a lower quality violin wood, if it were more compact and heavier. Therefore, if we use this testing method, we should also determine the weight of the wood. As I have already mentioned before, the best way to have certainty about the sounding characteristics of a resonant wood is to decrease the spruce plate (naturally with arch) to 4 or 3.5 mm for having a certain equable thickness and to define its side-tone, as well as its weight. With this methodology, it is desired to raise the pitch of the middle part especially. Naturally, some experience is required to be able to make a comparison. Finally, the determining factor is the result with the glued plate, when the plate is glued temporarily after an approximate elaboration. That is the way how we determine the side-tone. If the tone is deeper than expected, then put aside the wood. In the case of maple, we should start from the same point of view and use a similar testing methodology. If the well-sounding maple also has a nice flaming, it is even better since the violin will be more valuable for a lot of people. If the ribs’ waviness (wood texture) is identical with that of the back plate, it enhances the good look of the musical instrument. However, a wider flaming wood presents more difficulties in blending so it is recommended to choose a dense flaming maple for the ribs. The age of the wood to be used is not so important than before. It is a strict requirement that the wood has to be stocked until the point when it runs completely dry. Bagatella intended 3 years for drying, but it has to be taken into account that this waiting period was valid for the Italian climate. In other regions even 5-7 years are needed.
As the age of the violins was considered as a favourable advantage, which was an overestimation, it was believed that the same advantage was available to reach by using very old wood. Information about old and new violins, violas and cellos, as well as about making musical instruments can be found on the Cremonae violin auction portal.
James Cowel, November 25, 2016.
Resources:
– Adolf Heinrich König: „A Viola da gamba
– Franz Farga: Violins and violin players
– Josef & Reiner Hammerl: Erzeugung feinster Geigenlacke
Source: ArticleCube