Gut Strings

An introduction to gut strings on the lute and brief historical considerations

Historically, lutes were strung with gut, which gives a very different sound and feel from today’s common  stringing possibilities with synthetic materials. Lutenists wishing to hear their instrument’s true voice should at least once try gut stringing, and the following guide explains how to do this.
Our first step will be to work out whether it is possible to string our lute with gut at the pitch at which we want to play it. All gut strings break at more or less the same pitch on any given string length, irrespective of diameter; only the breaking tension varies. This may be counter-intuitive but is a fact that gives us a constant factor from which to calculate a working pitch. First we have to convert our string length (measured between the insides of bridge and nut) into meters: e.g. for a 60cm g’ lute that will be 0.6, and then divide 220 (our above mentioned constant) by this number. The result is the frequency in Herz of the highest note to which we can tune a gut string at that string length. With the best quality strings it is a conservative estimate, leaving a safety margin of at least a semitone. For reference, the frequencies of the commonest top string notes are: a’ above middle c’: 440. g’ sharp – 415; g’ – 392; f’ sharp – 370; f’ – 349, e’ – 329. Our 60cm lute gives us a frequency of 366.67 Hz, or f’#.
If the resulting figure says that our stringing ambitions are realistic, we now need to work out exactly which strings to use. The manufacturing processes and terminology used for modern gut strings are often not the same as those used for historical gut strings, about which we have little reliable information anyway. This guide follows the straightforward terminology used by Mimmo Peruffo, who has pioneered the recreation of various historical string types now widely used by professional players. Other manufacturers have their own string types and terminology, but the basic principles are few and present no problems once we have understood by what criteria we want to choose our strings.

Treble strings

Treble strings are the thinnest, tightest and most used strings on a lute and require the maximum possible tensile strength. Therefore they are always made of low-twist plain gut, which simplifies selection. We just need to know what gauge and length we want, and then choose a finish. Gauges and lengths are discussed at the end of this leaflet. Finishes mean oiled versus varnished, rectified versus unrectified. Historically, only unrectified oiled strings were available. Oiled strings are cured in oil during manufacture (the finished strings do not feel oily!) and are considered by most players to have a better sound than varnished strings. However, varnished strings are less affected by climatic changes (which affect tuning stability) and are more resistant to extreme skin chemistry – though some players find that their fingers squeak on the varnish. If our sweaty fingers turn the wire on your wound strings black or green, we may be better off with varnished gut, otherwise we rather go for the oiled strings.
Gut is a natural material with inherent irregularities. A finished string which is very irregular along its length will not fret in tune, therefore most strings are rectified mechanically as part of the manufacturing process, to remove any possible irregularities. Some surface fibres are cut during this process, so the resulting string is a little weaker, but because it is evenly round along its length it frets in tune. Unrectified strings are polished by hand, and can retain some irregularity. Their trueness can vary and some may not fret perfectly in tune, but they are stronger and last longer than rectified strings and their tone and sustain is unmatched by any other kind of string.

Mid-range strings

For mid-range strings (3rd-4th courses on Renaissance lutes, 3rd-5th courses on Baroque lutes) we have a choice of plain gut or ‘Venice’ strings; the latter are indicated with a ‘V’ after the gauge number. Plain gut strings in these gauges are made from many strands of gut, with a higher amount of twist than the thinner ones, and are therefore called ‘high twist’. This is done to give them flexibility, which in turn gives better intonation: if the strings are not flexible enough, the lateral displacement produced by fretting will cause the notes to go sharp. Venice strings are made with even more twist and are therefore more flexible; they have a brighter sound and fret better in tune than plain gut. They are more expensive but also extremely durable and their superior quality is clearly audible on gauges from about 0.8mm upwards, particularly on fretted courses. For thinner gauges and upper octaves of unfretted bass courses, regular high-twist gut is fine. We have the same choice of oiled or varnished finish, but these strings are always rectified so we do not need to specify this.

Bass strings

Here we have a lot of choices. On a few instruments such as the six course lute, Venice strings will work well right down to the bass, producing a focused sound and longer sustain than regular plain gut strings. If we need lower notes on a relatively short string length we will need heavier strings, and here we meet the big problem in stringing a lute with gut. We want bass courses with a strong and focused sound but we cannot simply keep increasing for ever the thickness of the strings to achieve lower notes. A very thick plain gut string sounds dull, is too inflexible to fret in tune and feels unwieldy under the fingers (and would not pass through the bridge and peg holes of historical lutes). Assuming that such a string already has the maximum possible twist, the only option is to somehow increase its weight. Gut can be made denser by impregnating the raw material with metal salts (loaded strings), or a finished string can be made heavier by wrapping metal wire around it (wound strings). Loaded strings are the closest modern equivalent to the red basses we see in many 16th and early 17th century paintings. They are red-brown in colour, have a smooth finish and are significantly thinner than their plain gut equivalents. They are easy to pluck and fret, have a firm, focused sound, and sustain a little better than Venice strings. They are the best choice for unfretted courses, e.g. the lowest courses of baroque lutes. Because gut tends to absorb metal salts unevenly, some strings may suffer from intonation problems when fretted.
Wound strings were not available until the 1660s and there is no evidence for their widespread use until the 18th century. Historical strings could be ‘demi-filé’, open-wound (literally ‘half-wound’), with a gap between the spires as wide as the diameter of the wrapping wire, or close-wound, with the winding entirely covering the core. A close-wound string is heavier than a half-wound of the same gauge and therefore best for the lowest basses and/or shorter string lengths. The winding may be of silver for a brighter sound, or copper for a warmer sound. Wound on gut strings have a focused sound and a shorter sustain than modern wound on nylon strings.

Working out gauges and lengths

To work out gauges we need to know a lute’s string length(s), measured between the inside of nut and bridge, the note to which it is to be tuned (g’, d’, a, etc), and its pitch (A440, A415, etc). Note also whether each course is single or double, octave or unison strung. Ideally we need the tension of each string as well. String manufacturers Aquila Corde Armoniche (www.aquilacorde.com) offer an online string calculator on their website. If we type this information into the appropriate spaces, it will work out the gauges we need. Note that the different types of strings are all calculated by their plain gut equivalent, so if we work out the gauge we need for plain gut and then decide to have a Venice or loaded string instead, we can just keep the same number and add ‘V’ for Venice or ‘C’ for loaded. It is normal practice to reduce the tension across the lute as the strings become thicker; this gives a certain feeling of equal tension, which is desirable. A single top string should be appreciably tighter, about 50% than the individual strings of the second (double) course. From the second to the fifth courses, the tension should be slightly reduced with each successive course. From the fifth course downwards we can use the same tension on each course. If we do not know our string tension we can work it out from our lute’s current stringing, irrespective of material, using the same online calculator and string conversion charts. Plain nylon string gauges (but not fluoro-carbon) can be converted to their equivalent gut gauges by multiplying them by 0.91: e.g., a 0.50mm nylon string is equivalent to a 0.45mm gut string. For those who do not know their lute’s current stringing details, some specimen stringing lists are supplied at the end of this leaflet, for some common lute types at average tension. Those who do not have access to the web can obtain a reasonably priced string calculator from Bernd Kürschner (Obere Waldstrasse 20, D-65232 Taunusstein, Germany. Tel. +49 (0) 6128-6910). If we are still unable to work out the tension, most string dealers and makers will work it out for us: this information should always be kept in the case with our lute. To work out the total length needed we shall add together the sounding length of the string (bridge to nut), the length from the nut to the appropriate peg, plus around 10cm to allow for tying on the bridge and winding on the peg. The standard 120cm length is adequate for almost all lutes except archlute and theorbo diapasons.

Fitting, and caring for, gut strings

We should be careful not to kink strings as we fit them: such kinks are weak points and may affect the sound. Otherwise, gut strings are easier to fit than nylon because they are less slippery. They will usually grip easily on the bridge, negating the need for multiple twists, knots or burnt nodules on the string ends. The easiest way to attach thin strings to the peg is to push about 2cm of string through the peg hole, twist the short end around the main length a couple of times, and then wind the string up on the peg. To avoid possible string jams and breakages, it is advisable to wind the string so that it does not press against the wall of the pegbox.
The thinnest strings will last longer if we detune them by about a tone between playing sessions. They settle to pitch very quickly when tuned up again. We ought to make sure that nut grooves are smooth and well polished, lest strings fray at this point. Any hairs which sprout from the surface of a string should be cut off close (a nail clipper does the job quite well) because they deaden the sound of a string and may cause further unravelling. We can slightly improve a string’s performance by first tying it on the bridge, rolling it between our fingers to introduce more twist (it must be rolled in the direction of the existing twist), then fixing it to the peg. The life of an unvarnished gut string may be prolonged by a very light coating of almond oil. We put a spot of oil on index finger and thumb and run the length of the string between them: it is a non-siccative oil so it should be imperceptibly fine.

by Lynda Sayce, with advice and assistance from Mimmo Peruffo and Ivo Magherini.

Brief considerations on historical stringing

We shall never know the true historical sound of the lute, if there ever was one; still, it is possible to spend a few thoughts about what was available to the ancients, in terms of strings, and what we can plausibly expect in terms of sound.
Excluding all the materials that were certainly not available in the past: nylon, nylgut, PVF (‘carbon’) and all kinds of wound strings employing such materials, all the ancients had at their disposal was gut, gut or gut, plain or treated.

Plain gut

The only possible variables here are kind and degree of twist, which can be:
– low, for maximum tensility
– high, for more resiliency
(tensile resistance and resiliency are the two deciding parameters affecting a string’s acoustical performance and are antagonistic: a high degree of twist increases resiliency and diminishes tensility) 
– double twist (or ‘rope’ construction – the modern, and much discussed, term catline enjoyed some favour in recent times): two or more strings are twisted together in order to obtain the highest possible degree of resiliency from the lowest basses; as stated above, the latter possess the lowest degree of tensile resistance, but since they work at a fraction of their breaking tension that is not a problem

Treated gut

– reinforced trebles (cantini rinforzati in Roman inventories) from the late 16th and the 17th centuries: it is plausible to assume that the gut underwent some chemical treatment in order to make it stiffer and more resistant to abrasion, keeping tensility unchanged. Today, too, it is common practice to treat strings with alum (aluminium potassium silicate), for example
– loaded gut: the acoustical limits of plain gut bass strings can only be overcome by increasing its specific weight: this can be done by treating fresh gut with metallic salts before twisting, or by winding metal wire on the finished string

The technological skills for such processes were long known, at least in other fields. How much of that know-how was actually employed in the manufacture of musical strings is open to speculation.
The processes for incorporating metal salts like cinnabar and litharge into materials like cloth, silk, leather, hairs etc. is already well documented in the second half of the 16th century (e.g. Plichto de tintori, 1568), while Alessio Piemontese (I secreti, 1555), describes how to produce the finest copper powder (which by the way turns out to be the same colour we see in so many iconographical sources from the early 17th century).

Wound gut strings

The tradition of winding metal wire on a thread core dates back at least to medieval fashion. Early records of such practice applied to gut strings date back to the mid-17th century. The winding could be open (the French called it demi-filé) or tight, depending on the amount of weight that was to be added to the string.
Metal wound on a silk core makes its appearance in the second half of the 18th century and lies beyond our historical interest.
Gut and wound silk strings, incidentally, remain in use until the middle of the 20th century. The synthetic fibers like tynex (nylon) in use today were originally developed for military purposes (parachutes) and only after the war came into common use (for some obscure reasons the yanquis preferred stockings to lute strings, to conquer the hearts of the liberated European women).

Historical overview

So what sort of strings would it be plausible to expect on the lute in its long history?
– Six course lute: all plain gut, single treble, octaves from the 4th down, low or high twist; basses presumably double twisted (rope construction) – it is ascertained that the latter was in use at least as from the end of the 15th century (and possibly already in Roman times) and is supported by the presence of orditori (rope twisting wheels) in the inventories of Roman string makers in the 16th century and until around 1570
– Vihuela: coeval and homologous with the six course lute in Spain and territories under Spanish domination (in Naples, like in other Italian regions, it was known as viola da mano, e.g.). Here the treble is double. The modern practice of tuning all six courses in unison contrasts with what can be inferred, at least indirectly, from available historical information
– Seven to ten course lutes: commonly double, or single trebles
Around 1570 there obviously was a technological ‘leap’ which allowed to lower the bass register by a fourth or a fifth below the 6th course. (A. le Roy, in 1574 talks about a new invention by which The Lutes of the newe invention with thirtene strynges…where the laste is put be lowe…is thereby augmented a whole fowerth).
Since nearly a whole century will go by before we find any mention of wound strings, it is plausible to envisage some kind of ‘loading’ treatment of gut.

The octaves question remains open: Dowland requires unisons down to and including the 6th course, other sources require octaves from the 5th down. Practice probably differed depending on period and/or region.

Lutes in D minor: Baroque practice always requires octaves from, and including, the 6th course down. Iconographical sources from the 17th century depict loaded strings in the low register. It is plausible to hypothize the use of half-wound basses in the 18th century
Theorbo (Chitarrone): double fretted strings were the rule. We lack any information about the use of octaves, on the other hand it is hard to imagine a scope, on such large instruments, for double courses if one does not intend to exploit the advantages offered by octaves

Rare iconographical sources depict loaded strings being used in the lower registers, although, strictly speaking, they are not really necessary.

Archlutes: double trebles were the rule, although there are cases of single trebles both on historical instruments and on iconographical sources. On instruments with long extention there is at least one iconographical source depicting loaded strings I know of

The use of octaves on instruments with short extention would imply the use of plain gut basses.

Guitars: the reentrant tunings in use in Italy work perfectly well with plain gut strings, whereas it is proven that wound, both open and tight, strings were used as fundamentals on 4th and 5th courses on French guitars in the 18th century