The Exploded Bow-SOUNDBOX 12th January

Posted on January 7th, 2010 by


Tuesday January 12th 1230pm

String Gallery, Royal Academy of Music Museum, Royal Academy of Music, Marylebone Road, London, NW1 5HT (02074805145)

 The Exploded Bow (A preview)

The Bow in use over timeAny bow bears the marks of its usage, from the constant fraying away of the bow hair, to the less recognised indications of specialised techniques, such as the scratches on the top part of the stick caused by col legno playing.

Close up of a used bow hair at 50x magnification. The hair has a mean diameter or ca. 0.230mm. Rosin deposits are visible on the hair.

Some aspects of the bow’s design have altered over time to accommodate changing playing techniques-to make the instrument more comfortable to hold, to function better whilst executing different strokes, or held in various ways. Others have not; some of the additions to the bow can be seen as temporal, even temporary, transient adjustments to accommodate the morphing fashions of performance and composition. Even in the relatively short time that the modern ‘Tourte-model’ bow has been in extensive use, there have been many of these.

We can come to a better understanding of the relationship between the construction and adjustment of the bow, as set off against the marks of its use, ‘performance weathering’, erosion even, by observing these changing approaches to the instrument, and the  attendant demands of colour and articulation. Through this we might be better able to imagine the manner in which various schools and various players, in close concert with the composers of their day, have used or imagined the bow.

 The Bow and the Hand

The sweat and oils in the hand are damaging to certain parts of the bow.

 Every string player will recognise the characteristic curve of grease which gathers on the portion of bow hair closest to the frog. This is caused by contact with the back of the right hand thumb and nail. It can cause the bow to adhere less effectively to the strings. Earlier bows were expected to often be used with the left hand thumb on the hair. Naturally, this would result in increased build-up of dust and grease on this portion of the hair. However, this was clearly not a factor in performance, as the ‘heel’ end of a ‘baroque’ or ‘classical’ bow is less effective than in a Tourte-model bow and therefore less used. So a grease build up in this region is less of a factor in performance. Curiously this grease build-up is more often seen on bows used by children and non-professional players. There are two possible reasons for this. One, children may be less careful about playing the instrument with clean hands, and two bows used by professionals are more subject to constant use, causing hair loss, so rehairs tend to take place more often, before the dirt has built up.

 The mother-of-pearl fittings which do not come into contact with the right hand in performance have a tendency to oxidise and crumble.

 Thumb band

Most modern bows are fitted with a leather band around the stick, which when the bow hair is slack will rest close to the ‘frog’. This provides a resting place for the right hand thumb, and leverage for colour and articulation. Indeed, most players will carry a callous on the right side of the tip of their bowing hand thumbs, where this band presses and rubs in performance. This band is a comparatively modern invention-not generally seen on bows in a purer form from the beginning of the 20th century. It represents a move away from the bowing techniques advocated by 19th century virtuosi such as Joseph Joachim, who leant into the ‘frog’ with the other side of the thumb. Indeed, Joachim recommended filing down the wood of the frog if it was not comfortable under the thumb.

 Wear and Tear

Some of the damage caused to the bow is not related directly to performance.

  A characteristic of certain bows is a ‘cinching’ of the nut, where the central decorative band of wood, mother of pearl or tortoise shell is worn away by winding the bow up and down, leaving the surrounding bands of silver, gold or nickel proud. It was not until the development of the ‘tensionable’ bow, that this began to be an issue.

 On earlier models the use of easily abradable materials, such as wood, ivory or bone, for the nut, suggests that the practise of unscrewing the bow with every use did not become widespread until the 19th century.

 Changing playing techniques, associated with the post-Viotti schools associated with the ‘Tourte-model’ bow, demanded that the hair be used and inserted into the stick, at higher tensions, indeed, so that, when in use the stick is curved slightly straighter than its normal, designed, concave arc.

 The result of this is the that bow needed to be loosened a)-in order to prevent the hair from loosening and breaking over-quickly and expensively, and b)-in order to prevent the stick straightening. Because of the shape of the modern stick, loss of the orginal arc of the bow can lead to distortion, warping, or occasionally, the tip falling off. The prevalence of‘re-tipped’ bows shows that this is far from uncommon.

 Following from all of this, the nut had to made stronger, less susceptible to wear; solid silver examples are not uncommon. However, it is clear that it an element of these earlier, more aesthetically pleasing nuts was still sought.

 During the 19th century, bows aimed at the amateur market (where the instrument would naturally, be less susceptible to performance wear) were often fitted with fragile, decorative ivory nuts. One might suggest that the use of delicate materials, such as tortoiseshell, for the nut, is, in part, nostagia for these earlier designs, and seeks to actually result in the aesthetically pleasing wear (the ‘cinching) described above.

 Decay of the Hair

From the moment that a bow is rehaired, the hank of horsehair begins to deteriorate. As the bow is generally used in a tilted position, this invariably begins on the ‘weather side’ of the bow, that touching the strings the most (on the other side from the player’s hand). The speed of this deterioration, by and large depends on whether the bow is being used for impactful solo playing, or lighter chamber performance and orchestral playing. The behaviour of the bow starts to alter slightly as the band of hair is increasingly gathered on the ‘thumb side’ of the stick.

 Impact of the Strings

A careful examination of the underside of a bow in heavy use will indicate that the bow hair will not protect the stick from erosion by the strings. However, the most common feature of this is a buildup of rosin and grease residue on the violin side of the stick, obscuring the varnish or French polish.  With the increasing use of metal and metal wound strings over the past century, this damage naturally has increased; gut strings are inevitably less likely to have the effect of filing away at the wood when the bow is used under pressure.

 Perhaps the situation was most damaging in the middle of the last century, when a large number of soloists, such as my teacher Louis Krasner sought the particular colour of metal strings played at high pressure with loose hair. Towards the end of the 20th Century, soloists began to use increasingly tight hair, which served to protect the wood from damage, as it did not come into so much contact with the strings.

 The dangerous 4th Finger

The most damaging part of the hand for the bow, is, curiously, the weakest finger, the 4th.

 In the 20th century an energetic remodelling of the ‘Franco-Belgian’ bow hold innovated by the school of Henri Vieuxtemps took hold, given literal heft by the bowing innovations of Carl Flesch and Ivan Galamian. These techniques relied heavily on the use of the 4th finger for control and balance, like the rudder on a large ship. As a result, the pressure and constant abrasion from this weakest digit increased, forcing many players to cover the ‘brazil wood’ with leather to prevent a hole being worn over the frog. This leather protection needs to be replaced regularly.