The philosophy

The violin as we know it, was improved by the cremonese makers in the 200 years from 1550 to 1750. They experimented constantly, tested by playing, and sought to understand the reasons for what they heard. Since then violin making has largely descended into the copying of instruments of the period without a rational understanding of what they were doing.

Stradivari experimented up to the time of his death. It seems certain, that had he lived longer he would have gone on experimenting. Should all experimenting stop because Stradivari died? Fortunately Guarneri del gesu thought not, and had the confidence and belief in the possibility of improvement, to continue the tradition of experimental development that was the real legacy of Stradivari's approach to violin making.

As violin makers, university trained towards asking questions and seeking answers, Harris and Sheldon could not be content to be merely copyists. They are motivated by a desire to understand why the violin is the shape it is, what happens if something is changed, and what it is tonally sensitive to. Answers to these questions are necessary in order to make better violins, but the questions can not be answered by visual examination of classical instruments, for this reason, in 1978 Nigel began a systematic program of make and play testing.




The shape

By a mathematical process of structural analysis, Nigel developed a theoretical understanding of how the violin body as a whole, deforms as the result of string vibrations and this showed that the vibrational patterns are very sensitive to the shape of the arching of the plates, and to the difference in shape between the front and the back plates. The theory is shown to be correct by both his PhD research program, and the systematic building and tonal testing of many violins. Through this program of testing, optimum arching shapes have been developed for the plates. The plate shapes used by Stradivari approximate to this on average, but where Stradavari has in some instruments deviated from it, the tonal tendency conforms to that predicted by Nigel's research. This largely explains why even Strads vary, some not being as good as others.

The arching shape has a very pronounced effect on the openness, the purity and the evenness of the sound, and particularly the power of the 4th string. Nigel has found that the arching shape also depends to some extent on the thicknesses used, so he therefore developed a method of modifying both the shape and thickness, to achieve the optimum result every time, even though the arching shape and plate thickness must vary from one instrument to another.

The instrument design that has evolved through this work looks very much like a strad of the late period; the rather straight centre bouts and upright sound holes stem very logically from the the need to maximise sound producing plate movements.





The plate thickness

Nigel Harris's research shows that the violin body is much less a resonator and rather more dependant on forced vibration than writers have supposed. The result is that the tone can be made much more consistent from one instrument to another by thicknesssing the plates to give constant flexural stiffness, rather than other methods such as constant resonant frequencies, or weight or thickness. Measuring the flexural stiffness directly, can be done roughly by bending and twisting the plates in the hands, (as was probably done in cremona), but to greatly improve the accuracy of this method, Harris and Sheldon do it by calculating it from the measured resonant frequency in several important vibrational modes, and the weight of the plate.





The varnish

Nigel and Roger have learned much from looking at all the evidence that exists about varnish, doing a large amount of systematic research themselves. The varnish that is applied to an instrument largely determine the type of sound it will have soon after its completion, as well as in the centuries ahead. But the manner in which it forms its interface with the wood, will largely determine the content of upper partials in the sound, and hence the carrying power of the instrument. If we assume for the moment that no one since mid 18th century Cremona has applied a varnish of the quality then existing, and that almost every other possibility has been used since, it would seem sensible to at least find and use in the meantime the best post Cremona varnish. This has been their approach. They have judged the success or otherwise of these varnishes not by how close they look to the cremonese, but how they sound, and how the sound has developed over a long period. They take no risks with that.
The overwhelming evidence shows that the Italian varnish tradition of Storioni, Pressenda, Rocca, and in the 20th century Bisiach, Fiorini, Scarampella, Candi and so on up to modern times, has been the most successful. These varnishes vary, but the common factor is the use of tree balsams (sandarac, mastic, elemi, Venetian turpentine, a little gum lac etc.) The Italian balsamic varnish is responsible for the Italian tone. This is the sound discerning players want.


Harris and Sheldon have found, that although this varnish produces an excellent sound, it is not as good as it could be in forming the most suitable interface with the wood. Generally Italian makers apply this varnish without any sealer to the wood and although it dries quickly, it still penetrates the surface and fails to achieve the very sharp cut off at the interface. Sealers are no help in this matter because their presence at the interface is harmful. Harris and Sheldon have found a method of making the surface of wood unreceptive to any penetration.
This gives their instruments very strong upper partials in the sound and is responsible for their exceptional carrying power. Violin number 39 was the first one to benefit from this, and they have used it on all instruments since then. The help of a university willing to examine samples submitted by them under the electron microscope, has enabled them to perfect these techniques. They took the best available and made it better. It is worth noting that many traditions of violin making have used varnishes (and still do), that depress the upper partials in the sound, because the instruments not being well set up sound better to the less perceptive player that way, particularly in small room.


Roger and Nigel have made a point of listening to their instruments at concerts, and could name several concert rooms of very unflattering acoustic which point up sharply the difference between good and bad violins. It is very difficult to tell by playing solo in a room, whether an instrument has the ability to project in a concert hall in real concert conditions. Roger is mainly concerned these days with the quest to produce a varnish which when scientifically and rigorously tested is undistinguishable from "old cremonese varnish". Roger and Nigel believe they are very close to achieving such a varnish, and the method of applying it. To date the varnish has not been used on a violin for sale, and they are in the opinion that it would not be tonally better, than that produced by the methods used since violin 39.





The adjustment

The better a violin is, the more sensitive it is to adjustment. The very strong content of upper partials in the sound of their instruments, does account for their exceptional carrying power, but if the adjustment is not correct, these partials can magnify the defect. They have learned how to adjust the instruments to get the best from them, and they urge all players who have their instruments to let them attend to any adjustments that may prove necessary.