SOUND POTENTIAL

Sarah Mnatzaganian of Aitchison & Mnatzaganian, the English cello specialists, asked me some questions for an article she is writing. ( She and her colleague Robin Aitchison, have organized a number of exhibits of contemporary cello bows.) Sarah’s questions have to do with the sound a bow generates on an instrument and they are good questions that nearly everyone wonders about.

Sarah: What makes bows sound so different?

Bows of course do not make sound themselves but they accentuate different ranges of an instrument’s potential sound spectrum as well as simply mobilizing more or less sound from the instrument. There are a number of elements contributing to the bow’s sound generating potential. First and foremost is the wood. The wood’s density, it’s grain structure, presence of perturbations in the grain, it’s stiffness and the quantity of extractives such as pigments and waxes in the wood can all effect the sound. Secondly there is the bow’s structure; it’s camber, it’s graduations or diameter from tip to butt, the height of frog and head, weight of frog and winding. Of course the qualities of the wood are reflected in the bow’s structure, strong wood will permit finer stick diameters for example. In addition the quality and quantity of hair has an effect. All these qualities of wood and structure are combined in an infinitely variable way in a given bow. The response of different instruments to this bow also varies, although certain qualities such as brilliance tend to be consistent.

Sarah: As a maker, how much control do you have over the sound of a bow during its manufacture? (for example, if a player asked for a bright sounding bow, would you be confident of fulfilling his/her request?)

As a maker one can definitely affect the bow’s sound generating potential. It helps greatly to have a stock of wood from one region that one comes to know over the years through trial and error. For instance when a stick from a particular board has certain qualities one can assume the sister sticks on the same board will be similar. Also one associates a certain look in the wood to a certain result. In the same way through experience one associates the mass of the frog or the amount and type of camber with a certain result. Brilliance in the sound can be achieved through choice of wood and other physical traits one puts in the bow.

Sarah: What makes the tone of some bows so much more interesting/complex in tone colour than others?

Richness or complexity of sound is a result of matching the right stick and the right dimensions. Once again we are beholden to the wood. There is always some magic to the overall sound signature a bow can produce; there is no simple formula and the maker is inevitably going to use their intuition as well as their knowledge. When players use poetic metaphors like ‘chocolatey’ or my favorite, ‘buttery’, the maker is going to mine all their experience to dig a stick out of their stocks that simply feels right in addition to having qualities that in their experience will produce the desired result. The instrument the bow is destined for is a large part of the equation as well.

CELLO BOW COMPLETED

Here is a recently completed cello bow shown in some earlier posts. It was made for Eric Jacobsen, a cellist based in Brooklyn, NY and member of the quartet, ‘Brooklyn Rider’. The completed bow weighs 79.9 grams with a winding of ‘argent sur soie’ or French tinsel.

THUMB PROJECTION

There doesn’t seem to be an established word for the part of the frog above the throat that sit behind the thumb so I’ll call it the thumb projection for lack of anything better. The thumb projection was always squared off by bow makers in the early to mid nineteenth century. In addition it was left with rather sharp angles because at that time, players often played with the hand further up the stick. By the time Voirin developed his distinctive light and rounded style in the later half of the 19^th century the hand position had settled further back with the thumb up against the projection; I believe like it is today. Voirin completely rounded his thumb projection and Lamy, Sartory and everyone else followed suit.

Many players preferred the earlier sticks and adapted to having their thumb on the angular frog and in most cases the frogs had become a bit worn, softening the angles. They normally didn’t put their thumb right on top of the projection like you can do with a Voirin and instead set the thumb on the thumb-leather and against the projection. But everyone transitioning fro a Sartory to a Peccatte would have to make this adjustment.

When early in my career I moved from the classic late 19^th century style to a style of bow rooted in the 1830’ies, I had to face the fact that leaving the thumb projection sharp would be uncomfortable for many of my clients. But rounding the projection as Voirin would have done on a frog like a Persois simply looks horrible and somewhat akin to grafting a camel’s head on a horse. I felt strongly that a stick that articulated in the early 19^th century style should look appropriately in that style as well. I decided that the answer was a fine chamfer instead of simply rounding off the angle a bit. A chamfer has the effect of keeping lines looking crisp and often the eye forgets its there. Rounding the projection slightly would make it look like the frog was antiqued in one place. I remember showing the luther, Bernard Sabatier on the rue de Rome, my first bow with a chamfered thumb projection. He didn’t like it. In time though, no one noticed it and players adapted to it well. Since that time I have never had a player not adjust in a week or two.

Cellists are manipulating a bow much more strongly that any violinist and it has become common for players to ask for surgical tubing over the projection and thumb leather. Although it lacks in aesthetic appeal it protects the bow in an area that can become quite worn. A common repair to cello bows is to graft wood into the depression worn in the stick by the thumb just behind the thumb-leather.

CELLO BOW HEAD

Now the cello bow head is carved and polished until it is ready for varnishing. In this case our head is styled fairly robustly with the front of the head rounded into the stick. On the other hand, the ‘dessou-cou’ or curve from the back of the head into the stick is fairly angular. The tension between the two curves gives the head its look.

The head on a cello bow is quite different from the head on a corresponding violin bow by the same maker. Traditionally the cello head sweeps forward compared to the violin head’s vertical stance. But originally, when the modern bow was being developed by Francois Tourte and some of his contemporaries, the cello head was sometimes cut like an oversized violin head. The forward sweeping head became the norm for a two reasons. First the cello bow is under proportionally quite a bit more tension than the violin bow and the head must be very strong. Sweeping the head forward allowed the head to be lighter and finer by transferring some of the stress into the stick. Since the cello head had a tendency to look heavy and bulky, makers and musicians appreciated the more graceful look of the swept forward heads. In the early to mid 19^th century violin bows were also occasionally made with a cello-like head. These are called swan heads or ‘col de cyne’ and have the back of the head rounded instead of defined with chamfers. Occasionally, several makers including Peccatte made cello bows in the ‘col de cyne’ pattern as well.

Through the course of the 19^th century cello heads became lighter and finer. Francois Tourte’s heads typically sweep forward but they are angular with a strong hatchet-like look. With Voirin and Lamy the cello heads became very fine and rounded and in fact they push the limits of adequate strength. In other stylistic details, cello bow heads follow their violin counterparts in the way the tip or ‘bec’ is shaped and the chamfers or ‘chanfrein’ are cut. But there is one exception. The tip plate or base of the violin bow head curves upwards while the cello tip plate is nearly flat. This looks better with the larger scale of the cello head.