Unbridled possibility

MAIN PHOTO CORUSS/DIGITAL GATE. INSET PHOTO CORUSS/CARDIFF VIOLINS/MAGDALENA CIESLAK

Say the words ‘synthetic bow hair’ to many string players and their first reaction might be, ‘What?’ and then, ‘Why?’ Musicians who haven’t heard of synthetic hair before may be surprised to know that there are multiple brands on the market. Some, such as Hervex and Maatzhaare, have been around for decades. Others, such as Zarelon from the US, and Coruss, developed in France, are more recent innovations. But why would players consider synthetic hair?

Maybe they don’t want their bows to contain any animal parts. Vegans who cannot avoid animal hide glue in their instruments can ‘veganise’ their bow by choosing synthetic alternatives to the ivory tip, the leather lapping, the mother-of- pearl eye and the horsehair. Players may be frustrated by the consistency, quality, affordability, reliability and durability of their natural hair. They might not like the cost of frequent rehairs and instead want hair that lasts longer than just a few months. Maybe they often play outdoors in humid conditions, and would like something more stable than horsehair, which is sensitive to moisture in the air and can stretch and become less responsive in a highly humid environment.

Putting these arguments aside, however, an obvious answer to the ‘why switch’ question might be ‘because synthetic hair performs better than natural hair’. Bow maker Benoit Rolland, based in Boston, Massachusetts, says: ‘As a musician myself, I would not trade natural hair for synthetic if the synthetic is of equal quality. I would only switch if the synthetic is better. When string players switched from gut to metal and synthetic strings, it was because the synthetic or metal strings were of higher quality and offered a better, more voluptuous, rounder sound. The same principle should apply to the bow and the hair.’ For Rolland, no synthetic hair has so far met his personal standards in terms of quality, but he is not surprised: ‘Imitating horsehair is extremely difficult. There are so many parameters to take into account.’

What are the challenges in developing a material that combines all the desirable qualities of horsehair? Bernd Musing, the creator of Arcus carbon fibre bows, has experimented with a range of different fibres in search of a practical synthetic alternative, and says that a key issue is the interaction of rosin with the hair and the strings. ‘To make the hair play well, the rosin needs to stick to the hair better than it does to the strings. That is a given with horsehair, but not with plastic fibres. You can sandpaper plastic fibres, you can put a metallic coating on them, you can do all kinds of tricks, but after a while the same problem occurs again and again - the rosin builds up on the string. That not only is annoying but makes playing impossible.’ Musing further contends that plastic fibres are often too elastic and flexible, heavier than horsehair, and have high levels of damping, which dulls high frequencies.

The makers of Coruss, however, believe they have a synthetic hair that matches horsehair for performance and handling, and surpasses it for durability, reliability and resistance to humidity. Launched at the end of 2012, Coruss came out of a joint research project by the French Institute of Textiles and Clothing and the Toulouse Chamber Orchestra, whose players wanted a hair that was both consistent in quality and reliably stable in different atmospheric conditions. Toulouse luthier Thibaut Carbonare, one of the co-founders of the brand, says that work is continuing to improve the hair still further, and that a new rosin, especially made for Coruss hair, will be available later this year. He does not say how Coruss addresses the rosin-adhesion issue posed by Musing - if, for example, the hair has a special coating - only that ‘the technique we developed to allow rosin to stick on the hair is part of our trade secret’. As to the elasticity of the hair, Carbonare says: ‘The quality and comfort of a bow’s performance depends on multiple factors. Elasticity of the hair is one of these, but there is also the flexibility of the stick, the musician’s playing habits, and so on. It is impossible to combine all these factors, because it would mean creating a different kind of hair for each musician. So we decided to create a single type of hair with an elasticity designed to t most bows and expectations.’

Coruss has proven durability, says Carbonare, who claims that some musicians using it haven’t had to rehair their bows for five years, though he advises changing the hair every three years. And besides appealing to vegan customers, another selling point of the hair is its availability in nine different colour options. But what do professional musicians think of its performance? For violinist Gilles Colliard, the Toulouse Chamber Orchestra’s musical director, the hair’s stability and consistency make it better than natural hair. He says: ‘It never breaks. It doesn’t stretch, whatever the humidity. And it always gives the same sensation, whether I play with a Baroque bow, a Classical bow or a carbon fibre bow.’ Colliard claims the hair is particularly effective in the strong articulation needed for Baroque music. When cellist Sarah Markle, who plays in the Charlotte Symphony in the US, switched from horsehair to Coruss in the autumn of 2018, she found that the hair provided clarity of attack as well as an increase in volume. ‘I have a relatively quiet French cello that doesn’t project in a huge way, ’ she says, ‘and the Coruss hair has done a great job of boosting the volume overall.’

Colliard recalls experiencing a slight difference in the reaction of the hair on the string when he started using Coruss, but says, ‘When you understand the reaction of the hair and adapt your playing, you can play any repertoire.’ One of Rolland’s concerns with synthetic alternatives to horsehair is that players risk physical problems if they have to change their bowing technique to get the best out of the material. He says: ‘Any missing quality in the hair will have an impact on the performance, possibly adding muscle stress if any lack of natural control compels the musician to compensate.’ For Markle, however, the adjustment from horsehair to Coruss was smooth: ‘I am sure there are a lot of micromotions that I’m not totally conscious of, but it was a very quick transition.’ Two of Markle’s colleagues in the Charlotte Symphony cello section have also switched to Coruss, but some of her violinist colleagues who have tried it are not so set on converting, after reporting certain hissing, extraneous sounds coming off the hair. But Markle says these violinists are nevertheless curious to test the hair’s hydrophobic qualities: ‘Like me, they play a lot of outdoor weddings and parties in the summer months, and they are still very interested in the hair for that reason alone.’

Coruss bow hair is available in nine different colour options

TOP PHOTO CORUSS/DIGITAL GATE. BOTTOM PHOTO CORUSS/CARDIFF VIOLINS/MAGDALENA CIESLAK

‘Any missing quality in the hair will have an impact on the performance, possibly adding muscle stress for the musician’ – bow maker Benoît Rolland

Synthetic bow hair is designed for stability and consistency

Both Colliard and Markle had to experiment with rosins to find one that worked best with Coruss. Markle initially used bass rosin as a base layer, as recommended by Coruss’s UK distributor Cardiff Violins, but soon settled on using just Magic Rosin. ‘I do notice that Coruss doesn’t absorb the rosin in the way that natural horsehair does, ’ she says, ‘but I don’t find that I’m applying the rosin particularly differently. Coruss just tends to take a little more rosin than natural hair.’

Markle came to Coruss as a vegan. The vast majority of bow hair is a by-product of the slaughter industry, and while some might argue that it is ethical to use the hair from a horse so that no part of the animal is wasted, Markle says: ‘I’m very much in favour of, where possible, not having a connection to the slaughter process. In mainstream conversations about food, clothing, cosmetics and even energy, people are increasingly asking, “Where does this come from?” and, “Who gets screwed over in the process?” I think more people are going to begin asking the same questions about their bow hair.’

But what about the environmental argument that replacing a natural product with a synthetic product simply adds more non-biodegradable material to an already plastic-choked planet? Markle urges people to consider the many thousands of mass-produced student bows. ‘These are often made of carbon fibre and are so inexpensive to manufacture that instead of being rehaired, they just get thrown away and replaced, ’ she says. ‘Carbon fibre is difficult to recycle and takes an extremely long time to break down in landfill, so it absolutely makes sense to fit these cheap bows with a synthetic hair that is much more durable.’

Musing, too, sees the purpose of synthetic hair for fractional- size student bows. He says: ‘Greater durability is an obviousadvantage, but also very young students aren’t usually performing in concert halls, so a strong sound is less of a priority. And for fractional bows the stiffness of the hair is less of an issue; hair that is more elastic can even be helpful.’ Colliard says he advocates Coruss because he knows many students who have had bad experiences with natural hair: ‘They end up having to pay out every three months for new hair, which adds a lot to the cost of studying.’ Rolland feels strongly that no student should suffer because of bad hair, whether it’s horsehair or a synthetic alternative: ‘Children deserve as good a material as possible, because they are learning, and learning with a bad material will hurt their musical development. Ask a professional to play a bow with poor- quality hair and he or she will still be able to perform. But that’s not the case with children.’

‘We should be flexible in our thinking and be willing to try new things’ - cellist Sarah Markle

What is the future for synthetic hair? Like any alternative material, it will come up against scepticism from traditionalists and those convinced that nothing could possibly improve on the natural product. Colliard argues that narrow-minded attitudes have led to active opposition among some violin makers. ‘There are luthiers who refuse to rehair with Coruss, ’ he claims. ‘Maybe commercially it’s not such a good proposition for violin shops, because the hair lasts so much longer.’ Where bow makers have already adapted to using alternative materials, the traditional materials they moved away from, such as elephant ivory, had become endangered and were subjected to trade restrictions, which is not something that is about to happen to horses. Markle simply wants the music world to be more open-minded towards horsehair alternatives. ‘We should be flexible in our thinking and be willing to try new things, ’ she says. ‘Coruss may be the best synthetic hair right now, but I am sure that others are working on developing their own products that could end up being even better. Coruss could be a stepping stone on the path towards a synthetic hair that even the most traditionalist of string players could get behind one day.’

Unconvinced though they are by the products available today, Rolland and Musing are both sufficiently persuaded by the arguments for a horsehair alternative that they are looking to develop their own ideas in the future. Rolland reasons that excellent horsehair is expensive and difficult to find, and that a high-quality synthetic hair could offer the musician an affordable, consistent and reliable alternative. The issues of cost and durability are driving Musing to look for a solution, and having previously experimented unsuccessfully with Kevlar fibres and those of the kind used in synthetic strings, he says that his latest trials with other fibres have given more promising results: ‘First tests have shown that the fibres are still a little too flexible and have slightly too much damping, but they produced a very clean sound.’

Synthetic hair may one day provide a real alternative to expensive top-quality horsehair

PHOTOS CORUSS/DIGITAL GATE

The ultimate synthetic bow hair may never replace horsehair but could instead become part of a musician’s equipment portfolio, to be used according to preference, application, touring requirements or atmospheric conditions. As Rolland explains, ‘Professional players have long integrated a panel of strings into their equipment, from gut to metal to synthetic, from which they select according to their instrument, repertoire and professional taste. Having a choice of bow hair would be appreciated, as long as its quality is proven at a high professional level.’