Northern Renaissance Instruments 6 Needham Avenue, Chorlton-cum-Hardy, Manchester M21 8AA, U.K. Phone & Fax. +44 (0) 161 881 8134 ; proprietor: Dr. Ephraim Segerman [USA] e-mail: firstname.lastname@example.org ; on internet: http://www.nrinst.co.uk
ABOUT STRINGS AND STRINGING
Over 25 years ago, NRI started researching and making strings for early instruments. Instrument makers wanted authenticity in the stringing to match the authenticity in their woodwork. Many of the original types of strings were no more available. Our research into the history of string technology and string usage has progressed steadily since our ground-breaking paper that appeared in the 1974 issue of the Galpin Society Journal. The historical information has been very useful to some, but most use more modern stringing because the traditions of the early-music movement developed before the research was done. We have learned to make almost every type of string used in Western music before the middle of this century, when a revolution in mechanisation and string design occurred. Our understanding of what gives a string musical quality, and our development of skills to produce that quality, has also progressed steadily since then.
Summary of String Types and Treatments
All-gut strings we offer include low-twist, high-twist and catline (or catlin) types. Catlines (which have a rope construction) can be 2- or 3-stranded, and polished (smooth) or unpolished (bumpy). Metals that we wind on gut can be copper, silver-plated copper and solid silver. The metal wire can be close-wound (with the windings touching each other) or open-wound (with small gaps between the windings) on a low-twist or high-twist gut core. What we call 'Tigerlines' have metal wire wound into the grooves of unpolished catlines.
All of our metal-wound gut strings are now given a chemical treatment (either modern or traditional with linseed oil) to retard moisture penetration, and so increases tuning stability and usually avoids the breakage due to loss of strength with high moisture uptake. This treatment, which we call 'Best', is available for unwound gut strings. It resists surface fibre formation, scuffing, and acid attack by perspiration. For smooth running over the nut, it needs to be well lubricated by marking the inside of the groove well with the graphite of a pencil. Less effective in all of these ways is a varnish treatment, which some customers prefer. There is a surcharge for both Best treatment and varnishing.
We also make strings with metal wound on silk fibres, and metal wound on silk wound on a steel core. The all-metal strings we offer include steel, iron and brass wire, rope twisted brass (in low, medium and high twist), and metals open-wound or close-wound on iron, steel or brass.
Summary of Historical Use of Strings
Most players of early instruments prefer to go as far towards authentic stringing as they can without sacrificing their expectations of good sound, good response to their playing technique, and blending in with their performing companions. These expectations constitute modern stringing traditions for these instruments. When an early-music convert asks us for a set of authentic strings, we almost always find that what is really wanted is what the early-music professionals are playing on. It is only for the adventurous explorer of historically accurate performance that the following historical information is useful:
Low-twist and high-twist gut (made, incidentally, from the intestines of sheep) have been standard stringing materials since at least ancient Greece. Twisting already twisted strings together to make thicker strings was practiced at least as far back an ancient Rome. Catlines differ from those by being maximally twisted to increase elasticity. The first evidence for catlines is from the beginning of the 16th century, but they became generally available only late in the 16th century. The evidence is against strings loaded with a metal or a metal compound ever being widely available. Strings with a metal winding were invented in 1659. By the end of the 17th century, they were often used on the lowest strings of some bass instruments as well as French violins. Strings called 'half-overspun' were between the lowest all-gut and highest close-wound string. They smoothed the transition in sound. History is ambiguous whether such strings were open-wound or tigerlines. They stopped being used by the end of the 18th century. It was not until the middle of the 18th century that Italian violins adopted a wound bass string.
Medieval musical instruments were all strung with gut except for psalteries and Celtic harps. An alternative for gut occasionally mentioned was silk, presumably in particularly humid circumstances where gut is weaker. Some harps used horsehair strings. Other harps and most psalteries used metal strings. Metals used were brass and silver, and occasionally gold. Iron was available as a string material only from late in the 14th century. In the middle of the 16th century, twisted brass and iron strings became available. High-twist brass ropes became available late in the 16th century, but they fell into disuse by the end of the 17th century. Late in the 16th century a very strong steel became available, but that availability ceased by the 2nd quarter of the 17th century. Only when piano wire was invented late in the 19th century was a steel as strong as this once again available. Iron strings of the 17th and 18th centuries were of phosphorus steel. No phosphorus steel is commercially available nowadays.
Except for the baroque guitar and the lowest strings of lutes, the tensions on the various strings on each fingerboard instrument were approximately equal during the 17th and first half of the 18th centuries. The baroque guitar had an alto tuning on a body with primarily bass resonance, needed higher tension on higher-pitched strings for sound balance. A similar progressively varying tension of the strings was adopted by Italian violins in the middle of the 18th century, when they started to use wound 4th strings. This practice spread steadily amongst violins until it became usual throughout Europe early in the 19th century. Violins remain unique amongst bowed instruments in having string tensions so unequal. Modern-baroque violin stringing includes this practice. That stringing can be characterised as of the 19th century type but at a tension level much lower than ever used except for that current in late 17th century viol-dominated France. We offer a brochure on authentic violin, viola and cello stringing.
Types of String Sound
A musical tone includes the sounding together of a fundamental pitch and higher pitches called harmonics (also called partials or higher modes). The more vibrational energy there is in the harmonics, the less relative energy there is in the fundamental. When one hears a tone with only fundamental and no harmonics, we consider it dull. If it is at a low pitch, we consider it unfocussed. With enough harmonics on the tone we judge the sound to be warm. With more harmonics (and relatively less fundamental) it is considered to be rich or bright or brilliant. With more harmonics (and less fundamental) yet, it is considered shrill or harsh or metallic.
The boundaries of acceptability between a dull and warm sound, and between a bright and shrill sound, as well as preference between a warm or bright sound, are all matters of taste. This varies according to expectations for different strings on the same instrument, as well as similar strings on different types of instruments. Taste in string sound has also varied historically, occasionally being quite different in different countries. The tendency in the 20th century has been for musicians to want more uniformity in string sound across their instruments than ever before, with brightness more valued than warmth.
String Properties and String Sound
Different string materials and/or string constructions are needed for high and low pitch ranges of an instrument. For the string at highest pitch, a material that has a high enough strength for its weight is needed to tune up to the pitch without breaking too often. If it is thinner, it tends to be brighter and less loud. If it is thicker, it tends to be warmer and louder. A second string of the same material and construction is thicker. At the same tension (and therefore the same loudness), because it is thicker than the first, it is warmer and less bright. There is a point where the thickness of a string of that material and construction is so great that the sound becomes too dull, or the string will sound sharp when it is stopped at the same place as thinner strings. At that point, one must change to a different string material or construction that is more elastic for its weight. Elasticity here means 'stretchability' like with a rubber band (technically, the inverse of the elastic modulus). The more elasticity there is in the string's material or construction, the more harmonics there are in the sound, and the less tendency there is for it to sound sharp when stopped. Such materials or constructions are generally less strong for the weight than materials or constructions with less elasticity for the weight.
Low-twist gut is gut at its strongest. High-twist gut is less strong but more elastic. The rope construction of catlines gives it more elasticity and less strength than high-twist gut. A gut string with metal winding has the weight of the gut plus the metal with the elasticity of the gut core alone (reduced to a small extent by the springiness of the metal coil). This reduction is less with solid silver winding because it is thinner for the weight, and this is why solid-silver winding gives a slightly brighter sound. By varying the relative amounts of gut and metal, one can get a variety of different elasticities for the string weight. For the same weight of string (which gives the same pitch for the same tension), the sequence of increasing elasticities of gut string constructions is: low twist, high twist, catline, tigerline, open wound, close wound with more gut and less metal, and close wound with less gut and more metal.
Some Practical Consequences
On most instruments (violas, cellos and double basses are exceptions), the highest string needs the strength of low-twist gut to reach the pitch without breaking too quickly. The types of all-gut strings that we recommend in our sets are the ones which offer the compromise between brightness and length of life that most musicians are satisfied with. Alternative types with greater brightness usually don't last as long. We can make catlines with lower twist for strings such as violin 2nds and viol 3rds that will almost as long as the usual high-twist string, but most don't consider the brightness advantage over high-twist ones noticeable enough to be worth the added expense. The choice between high-twist and catline violin 3rds is a matter of taste and the response characteristics of the particular instrument. Alternative types with less brightness can be chosen for economy when players are less fussy about brightness and stopping intonation.
The highest close-wound string on an instrument sounds considerably brighter than the lowest all-gut string. This difference is in the opposite direction than elsewhere on the instrument, and so sounds wrong. It can't be made warmer because thinner wire is too fragile. The 18th century solution was an 'half-overspun' string in between. The 19th century solution was to mask the difference in higher-position playing. The 20th century solution is winding with aluminium, which is a lighter metal.
The other close-wound strings we make, as they get heavier, add thickness to the metal faster than to the gut core. This tends to keep up bass brightness. The amount of shift in the proportion of metal to gut when going to lower pitches is traditionally different for different types of instruments. This is one reason why wound strings cannot be general purpose, and should only be made for specific instruments. Another reason is that we pre-stretch the gut at its playing tension before winding. If a general-purpose string was pre-stretched at a higher tension, its life would be reduced, while if it were pre-stretched at a lower tension, buzzing can more readily be induced by further stretching. If one wants to deviate from the traditional proportion of metal to gut, we will be happy to vary the proportion to suit one's wishes. A limitation is that a gut core thinner than a first string would break.
The Diameters on Our Lists
To get a string of a particular length to vibrate at a particular pitch and tension, it needs a particular weight. That weight can be provided by a solid gut string of the appropriate diameter, or a catline (which is not as tightly packed together as a solid gut string), or a gut core with metal wound on it. When the string is solid gut, the diameter given is the diameter one can measure with a micrometer. When the string is not of solid gut, we give the Equivalent Diameter (ED), which is the diameter that a solid gut string would have if it had the same weight. This makes calculations of weight and tension independent from the type of string construction.
A measurement of the outside or overall diameter (OD) will be about 10% larger than the ED for an unpolished catline, but the ED is a much more accurate measurement of weight. The OD of a metal-wound string is not a very useful measurement of string weight because the relative amount of gut and metal can vary considerably.
The graduations in diameter on the general gut-string price list, and from one set to the next heavier or lighter set on our instrument-strings price lists are in what we call 'semitone steps'. That means that adjacent diameters will sound a semitone apart at the same tension and vibrating length. For the vast majority of musicians, this difference in weight is just enough to make a noticeable difference in feel or sound. The graduations from 15 to 20 thou (.38 to .51 mm) on our general price list are 15, 16, 17, 18, 19 and 20 thou (.38, .40, .43, .48 and .51 mm). We regularly stock only those diameters (or EDs) amongst those listed that we regularly get asked for. We make the others to order. Other diameters can be made to order as well.
The one string quality we would like to be able to predict, but don't know how to, is the working life of a gut treble string. Gut, being a natural product, varies considerably in strength from one string to another and this affects how long it will last. Except for obvious flaws which are picked up in our routine testing, we do not know of a way to check the life of a string without shortening that life. A treble string, tuned to its "highest recommended pitch" for the string stop (as listed below) may last only a few days or it may last several months. A thinner string won't help because, for a constant material strength, the tendency to break from over-stretching depends on the relationship between pitch and string stop, and not on tension and diameter.
This relationship between treble-string pitch and stop is flexible in the sense that often a string can last the time of a recording session when tuned up to four semitones higher than this table indicates. Our recommendation corresponds with early practice as deduced from Praetorius.
A common cause of early breakage on treble strings is any sharp angle or rough surface bearing onto the string where it is at full tension. This may occur at the tailpiece, bridge, nut, or crossing over of strings in the pegbox. Also a string jammed tight where its peg meets the pegbox may suffer undue strain. If treble strings regularly break where they are fingered, Best treatment will practically eliminate this problem. Any gut treble string will last much longer if it is tuned down about a tone when not in use. If problems persist, ask our advice.
If a string breaks within a few hours of putting it on, providing the breakage was not on any of these places, and providing the string was not tuned higher than the above recommendations, then return the broken string to us for a free replacement. We would like also the string's original packet if possible. This is the best guarantee we can offer and still keep prices sensible.