Are Catgut Strings Still Meowing? The Surprising Truth About This Old-School String Material


Catgut strings refer to strings used on musical instruments that were historically made from the intestines of animals, usually sheep or cows. The origins of the term “catgut” are unclear, though some believe it derives from the use of cat intestines in early string manufacturing. However, while some early luthiers may have experimented with cat innards, cats’ guts were generally not suitable for string production.

The use of animal intestines for strings dates back thousands of years. Before 1900, the highest quality strings were believed to come from Italy, especially Naples, though other cities like Rome produced excellent catgut as well. Intestines were cleaned, twisted, and stretched to produce durable strings with unique acoustic properties.

While “catgut” has remained the term for this type of string, today they are rarely made from animal products. Most modern manufacturers use synthetic materials to emulate the sound and performance of traditional catgut strings.

Manufacturing Process

Catgut strings are made from the intestines of animals, usually sheep. The intestines are cleaned and stripped of fat and other material until just the elastic collagen layers remain. They are then twisted and wrapped around a metal rod to acquire the desired thickness. The twisted intestines are then hung up to dry and harden. This drying and hardening process, which can take up to 40 days, is key to producing strong, resilient strings. Once dried, the strings are cut to size, ground and polished into the finished product. The entire traditional catgut string making process is very labor intensive and requires precision at each step. Much of it is still done by hand today in a few specialized factories like Pirastro in Germany and Thomastik-Infeld in Austria.

Use in Instruments

Catgut strings have traditionally been used on string instruments like violins, violas, cellos, double basses, harps, and lutes. Before the advent of synthetic strings, catgut was the predominant material used for stringing these instruments. Catgut produces a warm, mellow tone desired by musicians playing early music on period instruments. According to UNLV, “Archetti musicians perform on original and replica baroque instruments that use catgut strings and shorter bows, allowing for a different sound and feel than their modern counterparts.” Catgut strings provide an authentic sound for historically informed performances of music from the Renaissance, Baroque, and Classical eras.


Catgut strings have multiple advantages that make them appealing to some musicians:

They provide a warm, rich tone that many feel sounds more organic and natural than synthetic strings. As the Encyclopedia Britannica notes, “Italian catgut is considered the best for stringing musical instruments” ( The natural gut material resonates in a pleasant way.

Catgut also provides a good grip on bows for stringed instruments like violins. The rosin adheres well to the textured surface. As an article on The Strad explains, the catgut material “is formed from muscle tissue that is designed to stretch and recoil” (, giving it an organic elasticity.

Many musicians also appreciate the feel of the authentic material and connection to traditional methods of string production. Catgut imparts a classic vibe.


Catgut strings have some notable disadvantages compared to synthetic strings. According to The Big Reason, catgut strings are less durable than steel or synthetic strings. They tend to deteriorate faster with regular use and need to be replaced more often. Catgut is also highly susceptible to changes in temperature and humidity. The pitch and tone can fluctuate significantly in different environments. As a result, musicians need to monitor and adjust the strings frequently. This makes catgut a high maintenance option compared to synthetic alternatives. Frequent tuning and replacement also makes catgut strings more costly over time.


Catgut strings have largely been replaced by modern alternatives like nylon, steel, and synthetic gut strings. Nylon strings were first introduced in the 1940s as an alternative to catgut. They have a bright, clear sound and are less affected by changes in temperature and humidity compared to catgut. However, nylon lacks the tonal complexity that catgut offers. Steel strings have a powerful, metallic sound and stand up well to aggressive playing techniques. However, they can sound harsh on some instruments. Synthetic gut strings aim to mimic the sound and feel of traditional catgut while improving durability and consistency. They combine aspects of both natural gut and modern polymers. Each alternative offers its own strengths and weaknesses compared to traditional catgut strings.

Source: MI Pro February 2010 Issue 117

Use Today

Catgut strings are still used today, but they are much less common than they used to be. While catgut was once the main type of string used on instruments like the violin, viola, cello, and double bass, most musicians today use synthetic strings instead.

Catgut strings are now considered more of a niche product. Some professional musicians still prefer the sound of real gut strings, believing they produce a warmer, richer tone. Catgut is also appreciated for its ability to vibrate freely. However, catgut strings are more finicky than synthetics – they are sensitive to changes in temperature and humidity, and need to be replaced frequently.

While catgut strings are not nearly as prevalent as they once were, there is still a small market for them. Luthiers and boutique string makers continue to produce catgut strings, mainly selling to professional musicians looking to emulate an old-fashioned sound. However, for most average players, the conveniences of synthetic strings outweigh the marginal benefits of real catgut.

Notable Players

Many famous violinists and other string musicians used catgut strings throughout history. According to Fein Violins, before World War II, catgut strings were the norm among top musicians. Violin legends like Fritz Kreisler, Jascha Heifetz, and Pablo de Sarasate all used catgut strings to achieve their signature sounds.

Female violin greats like Alma Rosé and Ida Haendel also used catgut strings during their performing careers according to a discussion on Alma Rosé was the niece of composer Gustav Mahler and led the women’s orchestra at Auschwitz during World War II. Haendel had a seven-decade career and was known for her powerful tone.

Many sources note violinist Jascha Heifetz’s preference for gut strings, especially for the A and D strings. His precise yet intensely expressive playing style was well suited by the warm, nuanced sound of gut. Other famous women violinists like Anne-Sophie Mutter have commented that gut strings produce a “mellower, more introverted tone.”


Catgut strings have been used for centuries to produce beautiful tones on string instruments. While many modern musicians use synthetic strings, there are some notable recordings that feature the warm, organic sound of true catgut.

One remarkable classical guitar recording using catgut strings is John Williams’ album The Seville Concert from 1986. Williams opted for catgut trebles on his Ramirez guitar, resulting in a rich, singing tone perfect for Spanish repertoire like the works of Isaac Albéniz featured on the album (source).

In the banjo world, Bill Evans’ album Native and Fine from 2011 showcases gut strings on vintage banjos. Evans was committed to using period-accurate catgut strings to authentically capture early banjo sounds (source).

While catgut may not be as ubiquitous as in centuries past, these recordings demonstrate the musical potential of natural gut strings in the hands of talented musicians.


Catgut strings have a long and storied history, dating back centuries as a material used in musical instruments like violins, guitars, harps and others. Originally made from actual cat or sheep intestines, modern catgut strings are usually synthetic, though some traditional string makers still produce real gut strings.

Catgut offers a warm, organic sound that’s valued by many musicians, though it can be high maintenance compared to steel or synthetic core strings. Real catgut is also vulnerable to changes in temperature and humidity. While catgut was once the dominant material for strings, most mass-produced strings today use steel or synthetic cores.

That said, catgut remains popular with professional musicians who appreciate its tonal qualities. Many luthiers and boutique string makers still produce high-end catgut strings, some from animal intestines and some from synthetic materials. Additionally, the sound of real catgut is still prized for historically informed performances of early music on period instruments. So while catgut is no longer the ubiquitous string material it once was, it retains an important place among discerning musicians seeking a particular sound.

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