The violin is the only musical instrument apart from ritual drums and Greek harps that has been deified.
The names of the violin parts have remained unchanged since ancient times: the head, the neck, the waist, the soul (or sound) post. The violin was created as an analog of the human voice. To this day, the timbre of neither the human voice nor the violin has been perfectly synthesized, even with the use of the most modern devices. Techniques, materials and ways of creating the violin were being improved over the centuries and have remained almost unchanged since the 18th century. The standard of violin construction has become one of the strictest among classical musical instruments.
Violin construction is very complicated in terms of physics, acoustics and strength of materials. It is a sophisticated acoustic device that requires fine tuning and regulation.There are many schools of violin production, but the brightest are believed to be the Italian, the French and the German schools. Each of them has its strengths and weaknesses and is very different from the others in terms of sound and craftsmanship. The sound of the Italian school’s violin is accepted to be the most mellow, plastic and manageable. The musician can manage the timbre characteristics of the instrument. The German violin is bright and hollow. The French one sounds a bit “glassy” and loud. However, in all schools there have always been instruments with “other” characteristics.
Let us look at the violins of the Italian school which was the most sophisticated and productive. Three types of wood are used for its production: maple, spruce and ebony. Depending on the wood’s characteristics it is used for making different parts of the violin. As the top plate is responsible for the bass strings sound, it needs the ideal combination of softness and resilience of spruce. Maple is used for making the back plate, the head and the ribs. The back plate is mainly responsible for the high register and the maple’s density suits these frequencies. The fingerboard is made of ebony, its high density and hardness (it sinks in water) is the most resilient to wear. The only competitor to ebony is ironwood, but it is too heavy and green in color.
The combination of maple, spruce and ebony is used in almost all wooden string instruments: the bowed instruments, the guitar, the balalaika, the domra, the lyra, the sitar, the harp, etc.
Many generations of craftsmen have experimented with different types of wood to make the violin (poplar, pear-tree, cherry-tree, acacia, cypress, walnut), but maple and spruce meet the acoustic requirements better than any. This has been proved by modern research.
The best wood for making the violin is grown in the mountains. The climate is the key. In the mountains the trees are subject to sharp changes of temperature and are not oversaturated with moisture. That leads to narrower summer layers and higher relative elasticity compared to the trees on the plain, and therefore better sound-transmission. The luthiers have traditionally used flamed or curly maple for the back plate because of its beautiful wavy pattern. We know the story of how Italian luthiers got curly maple. In the 18th century Turkey supplied maple for galley oars to Italy. Straight-grained maple was used for those oars. However, as it is difficult to reveal the wood structure before sawing it up, curly maple also arrived to the luthiers’ delight. As an aside, flamed maple is much harder to work with compared to the straight-grained one.
The “tuning” of soundboards is a stuff of legends and arouses much interest and debates. The Italians used the most complicated and efficient way which was perfected by Stradivari during the last 10 years of his life. According to physics the thinner and softer the material is, the lower it sounds or resonates the most with the lower frequencies. And vice versa — the harder and thicker the material, the higher its resonating frequency. So, varying the density and thickness of the material one can get the maximum resonance with a specific sound. The core of the tuning is simple. To each note made by a string there should be a spot on the plate which perfectly resonates with it and is also harmonized with the rest. The problem is that all sounds have several overtones which also should find “their own spot” and be harmonized with the others. Moreover, soundboards are under constant pressure caused by the strings (for example, the bridge presses down on the top plate with the weight of 30 kilos). Plate tap-tuning is one of the most complicated and important stages in creating a violin. The brilliance of Italian tuning is in its “totality”, as it takes into account all characteristics of any material. That is why straightforward copying of a unique instrument’s thicknesses does not lead to the desired result as there are no similar pieces of wood. Published maps of instrument thicknesses do not give any information if you cannot lay your hands on the plates depicted on the map.
The plasticity of the plates’ arching rather than the height is of sheer importance. All other parts of the violin (the head, the neck, the ribs) resonate too and, therefore, take part in the sound formation. Wood, being an organic and dispersed material, can absorb and lose moisture changing its mass and, therefore, the resonating frequency. This property is well known to violinists: the instruments change their sound in rainy weather. That is why the violin’s ground, about which there are so many legends, is so important. The process of covering plates with the ground is similar to the ancient Egyptian mummification. The materials are very similar and the aims are the same: to keep the material in the original state, to prevent moisture penetration and decay. In the violin making this process is more complicated: by permeating the wood with the ground we change its mass and, as a result, the quality of the sound. Moreover, by changing one part of the plate we automatically hurt its correlation with the others.
There are many myths about the secret of the sound of antique instruments. One of them says that the secret is in the varnish. It’s not true. The aim of varnishing is to protect the instrument from external factors, to emphasize the beauty of the wood and to not constrict the sound. When the varnish was washed away from one Stradivarius, the instrument started to sound worse. This happened because the varnish had been washed away with liquid solvent, and not removed mechanically, so some solvent penetrated the wood and altered its mass and density.
This is not all. In those earlier times, when the violins that amazed the whole world were created, their sound requirements differed from modern ones. The strings were different (made of gut), the neck was shorter, wider and attached to the body at a different angle, the bridge was different, and the tuning fork “la” was a half-tone lower than today.
So, now we hear the sound completely different from the one meant by the ancient craftsmen. From an acoustician’s point of view, the violin’s shape is not perfect. Modern research found out that the ideal shape is close to trapezium (like a small coffin). However, no one wants to play such violins.
The third string suffers the most in the violin. Even in the best Italian instruments it is weaker than the others. Modern strings producers take this into account. Now the authentic manner of violin playing and violin construction are being restored. It is much closer to the original aims of this instrument creation. In fact, all the antique instruments which have survived till our times are very fragile and have to be treated with care.
Musicians and luthiers have a concept of “playing-in” the instrument. It is applicable to both new ones and those that have not sounded for a long time and which have been restored. Even a simple action of releasing all strings and tuning them again changes the whole sound picture and must be followed by the ”playing-in” process. There are many kinds of tension interacting in the instrument. Wood is organic material, and its characteristics alter depending on external influences such as weather, the musician’s playing manner, even the weight of the chin rest. During the playing-in the instrument is “getting used” to the manner of the performer. A skillful musician can produce quite good sound with a mediocre instrument, but not many can make a great expensive instrument sound to its full potential. Very high skills are required for this, otherwise the instrument will just get used to what you can do.