The Truth About Catgut Strings. Do They Really Sound Different?


Catgut strings have been used on string instruments for centuries. The origins of the term “catgut” are unclear, though it was not made from actual cat guts. While early string makers may have experimented with using cat innards, catgut strings were usually made from sheep or goat intestines. Before 1900, the best strings were reputedly from Italy, especially Naples. Musicians believed the highest quality catgut came from that region.[1]

To manufacture catgut strings, the small intestines of sheep or goats were cleaned, stripped of fat, stretched, and twisted. They were often treated with lime as part of the curing process. The resulting material created strings with excellent acoustic properties well suited for string instruments. While many modern instruments use steel and synthetic strings today, catgut strings are still used by musicians who prefer their unique sound and feel.

Manufacturing Process

Catgut strings have a unique manufacturing process that starts with sheep or goat intestines. As described in detail on the Triwood1973 YouTube channel, workers begin by sorting and cleaning the intestines, removing fat and waste material. The intestines are then twisted into strings and polished to create a smooth finish. Finally, the strings are dyed using colors like red, blue, and violet.

According to the article on Today I Found Out, the intestines go through an extensive cleaning process: “Catgut strings are prepared by cleaning the intestines of fat and other undesirable additions. They do this by soaking the intestines in water and scraping them with glass or metal beads.”

Acoustic Properties

The materials used to make strings greatly affect their vibration and sound. Catgut, which is made from animal intestine, has distinct acoustic properties compared to metal strings like steel and synthetic polymer strings like nylon.

Catgut tends to produce a warm, mellow tone with a quick attack and relatively short sustain, though this can vary somewhat depending on the thickness and tension of the strings. Catgut has more elasticity than metal strings, resulting in a softer feel during bow changes on string instruments like the violin and cello. As described in the Catgut Wikipedia article, catgut strings are said to have excellent tonal quality, especially when just the right tension is applied.

By contrast, steel strings have a brighter, metallic sound with longer sustain. Steel transmits vibrations efficiently, yielding strong projection of sound. Synthetic polymer strings like nylon have their own character, generally with more warmth than steel but less than gut strings. While catgut was once the dominant string material, it has been largely supplanted by steel and synthetics for most uses.

Tone and Texture

Catgut strings are known for their warm, mellow tone. The natural fibers of sheep or goat intestines produce a nuanced and complex sound. Many musicians describe the tone as smooth and rich, with excellent sustain and a singing quality. Catgut is said to have better tonal gradation and texture than synthetic strings, allowing musicians to shape and control the sound with more nuance. The fibroelastic proteins in catgut absorb energy from vibrations due to their natural properties, affecting the tone in a unique way. However, the tone can vary between brands of catgut strings based on differences in animal sources and manufacturing[1]. While some modern polymers can imitate certain characteristics of catgut, many musicians feel the complex tone remains incomparable. The smooth playability and pleasing resonance of catgut makes it a favorite for instruments like the violin, cello, Baroque guitar, lute, and harp.

Modern Use

Catgut strings are mostly used by classical musicians today. Unlike metal or synthetic strings, catgut has a niche appeal and can be quite expensive, limiting its broader adoption. However, among classical players, catgut strings are highly prized and perceived as very high-quality.

As discussed in the Wikipedia article on catgut strings, “Historically, catgut was the most common material for the strings of harps, lutes, violins, violas, cellos, double basses, acoustic guitars, and other stringed instruments.”[1] However, the use of catgut strings today is mainly limited to the classical music community.

The niche status of catgut strings is largely due to their high cost. As explained in an article on WQXR, “The stringent demands of classical musicians have kept the industry small, and the production methods have changed little over several hundred years.”[2] The intensive handcrafting required results in much higher prices compared to synthetic or metal strings.

Despite the limited adoption, catgut strings are prized by classical musicians for their warm, complex sound. The natural material provides excellent tonal qualities that many performers believe cannot be replicated by other types of strings. The superior acoustics come at a premium cost, but for certain players, the extra expense is deemed worthwhile.

So while no longer the ubiquitous choice as in centuries past, catgut strings retain a devoted following among classical artists seeking the highest quality sound.


Personal Preferences

When it comes to musical strings, personal preference plays a major role in determining what materials a musician will use. While catgut strings have certain unique acoustic properties, many other factors beyond just the string material affect the tone and playability. The specific instrument, playing techniques, musical genre and style all impact the subjective experience for the musician.

Many musicians appreciate the warm, mellow tone of catgut strings. According to, some find the tone of catgut strings to be “sweet” and “singing” compared to synthetic or metal alternatives1. The organic material resonates differently than steel or nylon, producing a subtly different sound. However, the instrument construction, string tension, and other factors also change the final tone.

While catgut strings have a distinctive sound, many musicians prefer the brighter, projecting tones of steel or synthetic cores. The stability and durability of modern composite strings also appeals to some players. In the end, personal preferences in tone, playability, and cost determine if a musician chooses catgut over other options.

Scientific Analysis

Several scientific studies have attempted to objectively measure the sound and acoustic properties of catgut strings compared to synthetic strings like nylon or steel. One study published in the journal Catgut Acoustical Society in 2018 examined the mechanical properties and vibration behavior of various harp strings, including catgut, fluorocarbon polymers, and polyester [1]. They found that catgut strings had lower stiffness and higher internal friction compared to synthetic strings, which gave them a “warmer” sound.

However, the study acknowledged limitations in making definitive conclusions about perceived sound quality and player preferences based on mechanical measurements alone. The interaction between the player, instrument, and strings adds many additional variables that are difficult to isolate in an objective analysis. Ultimately, the study concluded that further research is needed to correlate measured acoustic properties with actual musical performance.[2]

While scientific studies can provide useful data points, there are still limitations in quantifying subjective qualities like tone and feel. The debate around catgut strings will likely persist based on the ears and preferences of each individual player.

Cost Considerations

Catgut strings are significantly more expensive than synthetic strings. A set of premium catgut guitar strings can cost $15-20, while a comparable set of synthetic strings is usually $5-10. Violinists must change strings frequently to maintain tone quality, making catgut a major ongoing expense.

With proper care, catgut strings can last for a month or more. However, the natural material does deteriorate over time. Musicians must weigh the superior acoustic properties against the shorter lifespan. For professional musicians investing in the finest possible sound, the extra cost is often worthwhile.

Beginners may want to start with less expensive synthetic strings until their skills develop. Intermediate players could consider a hybrid approach, with catgut for the wound strings most affecting tone.


While catgut was once the most common material for musical strings, various alternatives emerged over the years. In the early 20th century, silk strings gained some popularity as an alternative to catgut. Silk provided more durability than untreated catgut, but did not quite match the tone of quality catgut strings.

In the 1940s, Albert Augustine developed nylon strings as a synthetic alternative to catgut. Nylon monofilament provided greater durability and stability compared to natural materials like catgut. Augustine later developed a method of polishing nylon strings to improve their tone, which was adopted by major string manufacturers.

Other synthetic materials like polyester, steel, and various metal alloys are also used today for musical strings. Synthetic options allow for greater customization and precision in the string manufacturing process. The thickness, tension, and other properties can be finely tuned with synthetics.

While some musicians still prefer the classic sound of good quality catgut strings, the stability and options provided by modern synthetic materials have made them popular alternatives for instruments like guitars and violins.


In summary, catgut strings offer a warm, organic tone preferred by many musicians, especially for period instrument performance. The labor-intensive manufacturing process and sourcing of raw materials make them cost prohibitive for many modern players. While nylon and synthetic core strings provide more consistency and longevity, the unique sound profile of gut continues to have devotees.

Looking ahead, catgut strings will likely remain a niche product, valued by historical performers and those seeking an authentic sound. Advances in materials science may yield new synthetics that can mimic the tonal qualities of gut more closely. However, natural gut possesses inherent qualities that are difficult to exactly replicate. The future of catgut lies in small specialty makers and continued innovation to balance historical accuracy with playability and affordability.

Scroll to Top