Course:Phys341 2020/Tabla

The Tabla is an Indian percussion instrument that consists of two drums, one made of metal and one made of wood. It is the most commonly played drum set in North Indian music and is used to accompany vocal and instrumental music and dance.

Fig. 1: a SolidWorks rendering of a tabla done to show what it looks like in 3D. The model rotates to show the overall shape and proportions of the tabla.

History

The tabla is part of one of the oldest musical traditions in the world. The first references to melody and rhythm in Indian music are found in a sacred collection of literature in in the ancient Sanskrit language called the Vedas that date back to 1500 BC.

It takes its name from the 'tabl' of Arabic origin, meaning an instrument facing upwards with a flat surface. The instrument was originally used as martial drums which accompanied the military expeditions of Muslims. Eventually, it became a two-headed barrel-shaped drum called the pakhavaj which accompanied vocalists and instrumentalists and this evolved into the tabla (Fig. 1). The history of the tabla is debated by many scholars and modern research now suggests that the tabla was invented in the first half of the 18th century by a drummer named Amir Khusru. He was instructed to develop a more subtle and melodic percussion instrument that could accompany a new music style called Khayal which is now the basis of modern Indian classical music.

Physical Structure

Fig. 2: this is a labelled diagram of the tabla, detailing the names of each part and where they are located.

The tabla is made up of two drums. The left is known as the the bayan which is the left drum and the dayan which is the right drum (Fig. 2). The bayan is made of either clay or metal such as coper, bronze, or an iron sheet. The dayan is made of seesam, khair, neem or mango wood.Both of the drums have goatskin stretched across with multiple pieces of parchment referred to as the chanti, maidan, and syahi which are tied to a plaited strip called a gajara. The main differences other than size is on the bayan, the gajara is then joined to the bottom of the instrument by leather braces made of buffalo skin called baddhi which have eight small tuning blocks of wood referred to as gatta and are tied at an equal distance to the bottom ring, which has sixteen holes, to give the instrument equal tension at all points (Fig. 2). Also, the syahi is noticeably placed centrally on the dayan and off-centre on the bayan, making it the most important piece of parchment. The tabla is commonly placed on a padded ring called a gedi for balancing the instrument.

Dimensions:

Tabla Dimensions

Dimensions	Bayan	Dayan
Height	10.5 inch	10 inch
Playing Surface	10 inch	5 inch
Diameter of Bottom	2.5 inch	7.5 inch

Playing Technique

The tabla is played using one's fingers with strokes that are commonly called 'bol' with a series of syllables. The strokes are precise with each one functioning like a note in a melody with timbral and rhythmic structures are equally important and carefully integrated to match a vocalist. The tabla has a highly developed playing technique and in the hands of a master player it is capable of producing almost all the patterns of rhythms and cross rhythms in Indian classical music. It is a very complicated instrument due to the intricate hand movements and positioning required by both hands of the musician. Many bols have variations in spelling in pronunciation, as indicated in the table below.

Common Basic Tabla Strokes

Left Hand (Bayan)	Right Hand (Dayan)	Combination
Ghe/Ge	Ta/Na	Dha [ta + ghe]
Ka/Ki/Ke	Tin/Tun	Dhin [tin + ghe]
Kat	Naa/Na
	Te/Re
	Ra

Frequency Spectra and Time Development

Tabla strokes are typically inharmonic but strongly pitch resonant. It differs from other drums because it has a sustained character of tones due to a heavy rigid shell that favours sustained vibration of the drumhead which greatly increases the energy of vibration. The ring of leather known as the Gedi acts as a damper and the width is adjusted to obtain the desired tone. A broad ring will produce muffled short tones with few overtones and a narrower ring will produce prolonged and brighter notes with more overtones. It can be seen that some of the common basic tabla strokes vary in pitch according to a frequency spectra and time development analysis conducted on both the bayan and the dayan due to the difference in the materials of the drums.

Fig. 3: this is a MATLAB FFT of the stroke "Ghe/Ge" played on the bayan.

From the frequency analysis of the ghe/ge stroke played on the bayan, it can be seen that the pitch resides around 100 Hz, with two other peaks at approximately 290 Hz and 450 Hz (Fig. 3). The amplitude of the main peak is incredibly high.

Fig. 4: this is a MATLAB FFT of the stroke "Tin/Tun" played on the dayan.

From the frequency analysis of the tin/tun stroke played on the dayan, it can be seen that the pitch resides around 300 Hz with two other peaks at approximately 550Hz and 810 Hz (Fig. 4). This is very different from the bayan, which produces lower frequencies than the dayan. Played together, the strokes ghe/ge and tin/tun combine to create the stroke dha. There is a large peak at 100 Hz, and secondary peaks at approximately 300 Hz, 380 Hz, 550 Hz and 810 Hz (Fig. 5).

Fig. 5: this is a MATLAB FFT of a combination stroke of "Ghe/Ge" and "Tin/Tun" which create a new stroke called "Dhin."

Fig. 7: the skin of the dayan.

The difference in materials, along with the size of the gedi and playing technique of each note influences the pitch of each different tabla stroke on the bayan and dayan. In terms of materials, the bayan has a larger diameter of skin over the top (Fig. 6), it lessens the overall pitch while the dayan has less skin, making its pitch higher (Fig. 7). Depending on how tight the player adjusts the baddhi, they can also make the pitch higher (Fig. 2)

Fig. 6: the skin of the bayan.