Abstract

The tabla, a prominent percussion instrument in Indian Classical Music, is renowned for its distinctive sound and versatility across musical genres. This study investigates the key factors influencing the tabla’s tonal qualities, focusing on its construction, materials, and environmental influences. Specifically, the research examines the role of wood selection, leather quality, and syahi application in shaping the instrument’s harmonic overtones. Through a survey of tabla players, this study identifies diverse preferences regarding the effects of temperature on pitch and the choice of wood for tabla construction, highlighting the subjective nature of sound quality. The research also explores how environmental factors, such as humidity and temperature fluctuations, impact the tabla’s pitch and resonance, emphasizing the complex relationship between the instrument’s material properties and its acoustic performance. The findings underscore the importance of both craftsmanship and environmental conditions in determining the tabla’s sound, demonstrating its adaptability and enduring significance in Indian classical and contemporary music.

Keywords: Tabla acoustics, Timbre, Environmental factors, sound quality

In present times, Tabla is the most popular percussion instrument in the realm of Indian Classical Music. Majority of the Indian classical musicologist’s credit Amir Khusrau (1253-1325) for inventing the Tabla.¹ However, there is no mention of an instrument named “Tabla” in any of the treatises till the 18^th century. The first documented mention of the tabla drum in historical records dates back to 1745 in India.² Since then Tabla has evolved into a multifaceted instrument. The popularity of Tabla in almost all of the genres of present-day music, like Jazz, fusion, Indian classical, etc, gives us proof of its versatility. The protean nature of tabla arises from its irreplaceable melodious rhythmic beats which is a result of its unique structure. The Tabla consists of two drums: the “Daaya ” (right hand drum) and the “Baaya” (left hand drum). The Daaya is also referred to as “Tabla ” and the Bayaa is referred to as “Dugga “. The core structure of the daaya is made up of wood in contrast to the baaya which is made up of metal. The other parts of the tabla are made up of different kinds of leather.

Indisputably the tabla is the main accompanying instrument for all the forms of Indian classical and semi classical music.⁴ The popularization of tabla occured because of the crucial role it plays in accompaniment of khayal gayaki and over the years it has established its position as a solo instrument in the realm of Indian classical music. The tabla is a handcrafted, intricate instrument, and unlike most membranophones of the west, it has a unique ability to produce harmonic overtones. On the Dayan, the frequency created by the presence of the Syahi is tuned to the vocalist’s pitch or the tonic of the instrument being accompanied.⁵ Tabla can be described in as, “Tabla are collectives of carefully processed wood, metal, rawhide and tuning paste, assembled by artisans and struck by musicians, whose vibrations tickle the ears of listeners”.⁶

As previously mentioned, the tabla consists of two components: the dayan and the bayan. Each has five key parts that contribute to its unique sound:

• Kaath: The body of the tabla
• Pudi: The skin of the tabla
• Baddi: The leather straps
• Gatte: The wooden blocks/pegs
• Syahi: The black spot at the center of the tabla skin

These five components play a crucial role in shaping the timbre of the tabla. There are distinct structural variations between the dayan and the bayan; for instance, the dayan, typically smaller and crafted from wood, contrasts with the bayan, which is larger and made of metal. Furthermore, the positioning of the syahi varies between these two drums. This study specifically examines the factors that impact the sound of the dayan, also known as the tabla.

Sound quality in tabla is inherently subjective, making any independent assessment inconclusive. Additionally, the unique timbre of each tabla is influenced by the materials used in its construction. Consequently, tabla players’ preferences often vary based on the raw materials used, such as the type of wood or other components. These factors also lead to individual preferences for specific tabla makers, who craft instruments tailored to distinct playing styles and tonal qualities. To gather opinions of different tabla players a survey was conducted which consisted of following questions:

• What do you think is the effect of temperature increase on the tuning of tabla? (Pitch increases/decreases/remains the same)
• What do you think is the effect of temperature decrease on the tuning of the tabla? (Pitch increases/decreases/remains the same)
• According to you, how hollow a tabla should be to sound the best aesthetically? (Answer in percentage out of 100)
• Which wood do you think is the best for tabla? (Teak/ bijesaal /black sheesham / red sheesham / some other wood).

100% of the respondents were musicians, and 63.5% of them were tabla players. Among the tabla players, 68.75% said the pitch increases when the temperature rises, while 31.25% said the pitch decreases. When asked about the effect of decreasing temperature, 42.42% said the pitch increases, 39.39% said it decreases, and 18.18% said it remains the same. Regarding the best wood for the tabla, 51% of the tabla players favored black sheesham, 21% preferred Bijesaal, 15% chose red sheesham, and the remaining 13% selected other woods such as mahogany, teak, or Khair. The survey results clearly depict the diverse opinions among musicians and tabla players. But what are the correct answers to these questions? To understand the differences that arise from these varying opinions, we need to explore the science of the materials used in this handcrafted instrument.

Before elaborating upon the factors affecting the sound quality of the tabla let us first discuss the meaning of sound quality. Sound quality or “Timber” describes the characteristics of sound that helps us distinguish between different sounds.⁷ Timbre is determined by the harmonic composition of sound, which can be analyzed using Fourier transformation. A sound consists of a fundamental frequency and its overtones. The presence and intensity of these overtones are key factors that differentiate the sound of musical instruments. Even tablas tuned to the same frequency (e.g., 440 Hz) can sound different due to variations in the levels of overtones, which are influenced by the construction of the instrument. As a handcrafted instrument made from natural materials like wood, it is practically impossible to produce two tablas with identical tonal qualities.

Let us examine the parts of tabla that contribute to its unique sound. 

Kaath:

The core structure of the tabla is made up of wood and the type of wood used in tabla is crucial for its sound quality and durability. The types of wood commonly used are Sheesham (Indian Rosewood), Bijesaal (Indian Kino wood), Teak, and Khair (Cutch Tree). Wood frames (or shells) for drums generally have negligible effects on the sound from the membranes stretched with high tension at both sides.⁸ This statement might be true for instruments having shells, but for a membranophone which is solid at bottom this doesn’t seem right. The reason to disapprove from this statement is absorption of sound and reflection of sound within the hollow chamber of the tabla. According to popular opinion of tabla players and tabla makers, ¾ part of Tabla should be hollow from inside and ¼ part should be solid. To actually put light to the reason for such a variety of tabla available and difference in preferences of the wood used for tabla, we need to first understand the physical properties of the wood. It is well known that wood tends to shrink and swell as the relative humidity of the air changes.⁹ Therefore, the durability of the wood is crucial when choosing it for the tabla. Moisture content is an important consideration when selecting wood for the tabla. To make sure the moisture content is the least, the wood is seasoned (Seasoned- To season the wood, it is kept in a cool and dry place for almost 6 months or sometimes even more).¹⁰ The wood for the tabla is chosen by considering four characteristics:Dimensional Stability, Density, Insect and Fungus Resistance, and Acoustical Characteristics.¹¹

Types of wood used:

Indian Rosewood: It is of two types: Dalbergia Sisoo (Red Sheesham), and Dalbergia Latifolia (Black Sheesham). The Black sheesham is considered the better of the two. The sound produced by black sheesham wood tabla is resonant and clear. The density of Black Sheesham is around 850 kg/m³.¹² The density of the Red Sheesham wood is 770 kg/m³.¹³ Both the types of wood, as evident from their densities, are strong and durable. Both of them have good resistance to decay and insects and demonstrate good dimensional stability with minimal changes in size due to moisture. Usually, it contains a straight grain pattern or slightly interlocked.

Bijeysaal / Vijaysar: The density of Vijaysal (Pterocarpus marsupium) is found to be 800-880 kg/m³.¹⁴ Vijayasal wood (Pterocarpus marsupium) is exceptionally hard, durable, and close-grained with a yellowish-brown to brown heartwood that darkens over time.¹⁵ It is known for stable dimensions, experiencing low to moderate changes with moisture. Typically, the grain structure is straight to interlocked.

Khair Wood: The wood is heavy, strong, durable, and resistant to pests. It has a density ranging from 880 to 1000 kg/m³ at 15% moisture content.¹⁶ It exhibits moderate dimensional stability, showing moderate swelling or shrinking. The grain structure is generally straight to interlocked.

Teak Wood: The average density of teak wood ranges from 600-700 kg/m³.¹⁷ Teak is renowned for its excellent dimensional stability, maintaining size even in fluctuating humidity levels. Teak wood contains a straight grain pattern or sometimes it’s slightly wavy.

Let us now discuss the vibrations happening inside the hollow part of the tabla. My point of view is that when we strike the membrane of the tabla, the air particles inside the chamber vibrate similar to the vibrational modes of the membrane, which due to the syahi is harmonic in nature. High-density wood is expected to produce a sharper and clearer sound, as due to higher density, the particles of the wood are closer to each other, promoting reflection of higher overtones and decreasing the leakage of the sound through the body of the tabla. Now, if the density of the wood is low or the moisture content is high then the particles of the wood are able to absorb the vibrations and hence the sound more. Additionally, less density might be related to excess leakage of sound through the body of the tabla and hence decreasing the quality of the sound produced.

Black Sheesham, or Indian Rosewood, is the most preferred wood for tabla construction despite the higher density of Khair and Vijesaar woods, which theoretically should produce superior sound. The sharp sound produced by Khair and Vijesaar is not favored by all tabla players. Additionally, the scarcity of these woods in India makes them more expensive. In contrast, Black Sheesham produces a clear sound with fewer higher overtones, resulting in a warmer tone that musicians typically prefer. It is more readily available, has sufficient density to ensure durability, and produces a good sound, making it the most common choice for tablas. Furthermore, woods like Red Sheesham, Black Sheesham, and Teak generally offer more uniform and pronounced grain patterns, which are desirable for both aesthetic and functional purposes in tabla making. While Khair and Vijesaar also have suitable grain characteristics, they vary more in texture and require careful selection for optimal instrument construction.

Due to the uniform grain pattern in Black Sheesham, its workability is excellent, making it easier for craftsmen to shape and tune the tabla to precise specifications. Its resilience against environmental changes such as humidity and temperature variations ensure that the tabla maintains its sound quality over time. The balance of affordability, availability, and acoustic properties makes Black Sheesham a practical and effective choice for both novice and professional tabla players. Its widespread use in the crafting of tablas has also led to a deeper understanding and refinement in working with this wood, further enhancing its desirability among musicians.

Pudi:

The leather or skin used for covering Tabla and Bayan is called ‘Pudi’. The quality of the pudi plays an important role in the production of harmonic overtones. Premium goat skin is selected for its strength and flexibility.¹⁸ The skin is meticulously examined to ensure it is flawless and free from defects. How the goat skin is treated to make it usable for making pudi affects the sound of it. The goat skin is cleaned to remove fat and hair, soaked in water to soften, and then stretched and sun-dried to achieve the right thickness and texture. There are two ways to remove the fat and hair from the skin (this process is called “tanning”).¹⁹ First is by using natural materials and the second one is by using chemicals. Traditional methods for treating the hide include natural drying, oiling, and water treatment to retain its elasticity and enhance sound resonance. Modern approaches sometimes involve chemical treatments, which can whiten the hide, although traditionally treated hides retain a natural yellowish tint. Overuse of chemicals may stiffen the skin, reducing its ability to produce the rich, nuanced overtones that tabla is known for. The uniformity of the skin ensures that the sound produced from the tabla, at any particular position of the tabla, is similar in acoustical characteristics.²⁰

The goat skin stretched across both the drums is made of three layers of membranes, one full and the other on the periphery of the full skin.The first layer is called “bharti” which covers the rim of the “Kaath” and provides structural integrity to the pudi. The second and the third layer of the membrane is stretched over the tabla together with the help of strings. The second layer is called “Maidan/Lao”. The third layer is cut from the center to make it ring shaped and forms the “Chaanti” of the tabla. The pudi is then tied by the “Gajra” which is tied by either making 48 holes in the edge of the pudi in case of smaller tabla or 64 holes in case of larger tabla (>6 inches diameter) and is secured to the drum’s mouth with leather straps known as baddi, which are then tied to another ring at the instrument’s base. Sixteen evenly spaced holes ensure the braces provide uniform tension across the drum. A perfectly tuned drum is more resonant than an even slightly mistuned one.²¹

Syahi:

The Syahi, a black paste made from iron filings, gum, and other ingredients, is applied in concentric layers to the central membrane of the Pudi. This process, taking several days to ensure proper drying and even distribution, is crucial for determining the tabla’s tonal qualities and pitch range. For drying the syahi faster, and for consecutive application of the layer of the syahi, Basalt stone is continuously rubbed over the syahi.²² Once the syahi is dry, the pudi is stretched with the straps known as “Baddi”. The best-case scenario to get the Harmonic overtones from tabla, diameter of the syahi should be ½ of that of the pudi.²³ Having the syahi at the center, the drum is called as loaded. Non-loaded drums, or in general all the instruments with circular membranes, produce in harmonic overtones, which are in contrast to the vibrations produced by a string.

Theoretically, the fundamental mode (0,1), for a circular membrane, where the entire membrane moves uniformly, produces the lowest tone. The first overtone (1,1) has one nodal diameter and one nodal circle, with a frequency approximately 1.59 times the fundamental. The second overtone (2,1) features two nodal diameters and one nodal circle, with a frequency about 2.14 times the fundamental. The third overtone (0,2) has two concentric nodal circles, producing a frequency approximately 2.30 times the fundamental.²⁴ In the case of loaded drums, such as the tabla, harmonic overtones can be produced if the syahi is symmetrically applied to the skin. This phenomenon was first discovered by Sir C.V. Raman, highlighting the unique acoustical properties of the tabla that distinguish it from other membranophones. Experiments were performed by Dr. K. Varadarangan on mridangam, similar experiments can be performed for tabla, proving that it can also produces near harmonic overtones.²⁵

Different pitches in a tabla are achieved by varying the size of the kaath, which typically ranges from 5.25 inches to 7.25 inches in diameter. For instance, a lower octave tabla in C#, known as ‘Kharaj Tabla’ or ‘Mandra Saptak Tabla,’ usually has a diameter of around 7 inches, while a middle octave tabla of the same pitch is about 5.5 inches. Since its development 300 years ago, the size of the tabla has not been standardized and now varies according to the Tabla player and maker’s preference. With advancements in tabla making, a C# scale tabla can be crafted with diameters between 5.5 inches and 6.25 inches. However, the aesthetic quality of the sound can differ. Some tabla makers, to showcase their expertise, create larger tablas with high pitches, but these often lack in sound quality and skin durability.²⁶ To provide perspective on how the tabla’s sound varies with size, I recorded the syllable ‘Na’ played on both a 5.5-inch and a 7-inch tabla, tunes to C#. The distinct difference in overtones clearly illustrates the significant variation in their timbre.

Making style and playing technique plays an important role in the production of sound. Two major different styles of making and playing the Tabla can be considered by Calcutta style and the Bombay/Pune style. Assuming fine craftsmanship, the type of tabla also makes a huge difference. There are two different styles of tabla making, the Calcutta style and the Bombay style. To explain it in brief, Calcutta style tablas have thin skin and thin syahi, which tends to produce a sweet sound. On the other hand, Bombay style tablas are made of thick skins and mainly thick syahi which tends to produce a deeper and richer sound. Additionally, Mumbai drums have the reputation of being a lot more durable as compared to Calcutta drums.²⁷ Furthermore, different types of tablas lead to distinct playing styles, with performers using varied phrasing of tabla syllables, resulting in different sounds. Calcutta tablas, known for their rich and resonant tone, are favored for solo performances, whereas Bombay style tablas are preferred for accompaniment due to their sharper and clearer sound. As a Tabla player, I personally prefer the Black Sheesham tabla with Bombay style of making. The strong and resonant sound produced by these instruments is ecstatic to my ears.

The age of the instrument and tabla player’s instrument maintenance practices also plays an important role in the sound quality production. Tuning the instrument to different scales frequently deteriorates the sound quality of the instrument as it leads to expansion and contraction of the membrane which results in the decrement of its structural integrity. Maintaining a tabla on a fixed scale aids in maintaining its acoustical characteristics. Due to environmental factors the tension on the membrane is unequal so if a tabla is kept untuned for a while, its ability to produce nuanced overtones deteriorates.

Let’s understand how the environment influences sound production in a tabla. Temperature and moisture are crucial factors affecting the sound of a tabla. As per the survey data, the majority of tabla players (68.75%) believe that pitch increases with a rise in temperature, while 42.42% say pitch increases and 39.39% say it decreases with a drop in temperature. However, assessing pitch changes solely based on temperature is inaccurate because moisture plays an equally significant role.²⁸

Scientifically, materials expand when temperature increases, so one might expect the tabla’s skin to expand and the pitch to decrease with rising temperatures. Conversely, with a temperature decrease, the skin contracts, and the pitch should increase. This view contradicts the players’ opinions. The overlooked factor here is moisture. In high humidity, the tabla’s skin absorbs moisture, causing it to swell and loosen, producing a dampened sound. When the temperature rises in a humid environment, the skin loses moisture, contracts, and the pitch increases. Similarly, in low humidity and low temperature, the skin contracts, raising the pitch again. Thus, the pitch change in a tabla, in relation to the environment, depends on the combination of temperature and humidity.

Conclusion:

This study highlights the complex interplay of materials, craftsmanship, and environmental factors that contribute to the unique tonal qualities of the tabla. The choice of wood, particularly Black Sheesham, plays a crucial role in defining the instrument’s resonance and clarity. Despite the theoretical superiority of higher-density woods like Khair and Vijaysal, Black Sheesham remains the preferred material due to its balanced acoustic properties, workability, and availability. The quality of the leather (pudi) and the precise application of syahi further influence the tabla’s ability to produce harmonic overtones, a distinguishing feature of its sound.

The survey results reveal a diversity of opinions among tabla players regarding the effects of temperature on pitch and the optimal wood for construction, underscoring the subjective nature of sound quality in this instrument. Notably, while temperature changes are often cited as influencing pitch, the study also emphasizes the critical role of humidity, which has a significant, yet frequently overlooked, impact on the tabla’s sound production.

In addition to material factors, playing style, maintenance practices, and environmental conditions—such as temperature and humidity—further shape the tabla’s tonal characteristics. The findings affirm that the tabla’s sound is not only a product of its construction but also of the dynamic relationship between the instrument and its environment. This underscores the tabla’s enduring versatility and significance in both classical and contemporary musical contexts.

Endnotes:

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