Making a violin, viola or cello to produce a particular kind of sound is a complex balance of many factors:

1: The Pattern

The first is the actual pattern of the instrument. Although the outward form of the violin has changed very little since Andrea Amati’s first surviving  designs from the mid-sixteenth century, every individual luthier of the classical age of violin making made subtle changes which altered the sound of the instrument. The most radical and successful modifications were made by Stradivari himself. But even within the oeuvre of Stradivari, different forms produce different distinctive voices, with the earlier, ‘Amatise’ instruments providing a clear, bright tone, and the larger ‘Golden Period’ forms adding more resonance and power to the lower strings in particular.

2: The Arching

The second important factor, directly connected to the two-dimensional outline form of the instrument is the three-dimensional arching of the front and back. The precise shape of this arch has a very powerful effect on the kind of sound the instrument produces. A high, full arch will provide a darker, viola-like sound, a high arch with complex counter-curves around the edges emphasises the treble and gives a bright and very responsive sound, while a flatter arch can provide a more powerful soloistic tone.

3: Choice of Wood

Thirdly, the sound is shaped by the wood  itself.  Although spruce is invariably used for the front, and most often maple for the back, within these species the qualities of each individual piece of wood can vary tremendously. Softer wood will provide a more muted, rich sound. Harder wood will bring a ‘brassier’ influence, but both extremes can be balanced by other factors of the design. Maple can be sawn from the tree in different ways- ‘quarter-cut’ provides the stiffest orientation of the grain and the brighter sound, while ‘slab-cut’ wood has the grains aligned differently and is more elastic, and helps provide a more complex and diffused tone. Quite often other species are used for the backs of violas and cellos, where a broader, softer and more rounded sound is sought- poplar, willow, beech and other hardwoods can be used with distinctive effects.

4: The Woodworking

The actual working of the wood is the next determining factor in shaping the sound. The back and front are carved out to very close tolerances; a tenth of a millimetre either way can be critical, but the thicknesses have to be planned to suit all the other factors. The height and shape of the arch, and the strength of the wood both have to be accounted for in graduating the back and front, which also have to be kept in balance with each other.

5: The Varnish

Then comes the varnish. It often seems as if varnish actually has a negative effect on tone in practice. It could be said that the less you have on the instrument, the more responsive and exciting it is to play. However, the important point is that the varnish should not mute the instrument in any way, and it is vital that the wood is properly prepared so that the varnish does not penetrate the grain and muffle the clear, natural response of the wood. Furthermore, the varnish needs to be elastic and supple, able to move with the wood, rather than encasing it in a hard shell.

5: The Final Adjustments

The last, but not least, factor is the final adjustment of the instrument. The regulation of the bass-bar, soundpost, bridge, neck and tailpiece can make enormous differences to the sound and to the comfort of the player. Making all these aspects work together and in balance is certainly the most demanding part of instrument making, but can be the most rewarding in terms making a good sound, and a happy musician.