Membranophones

What are membranophones?

Membranophones (“Fellklinger”) are musical instruments which have a stretched membrane to produce sound. This is usually done by beating, as with a percussion drum, which is a percussion instrument. There are also rubbing drums, where the membrane is rubbed with an object, and plucked drums, known as ektara in India. All types of drums are membranophones. In the case of the mirliton, the membrane is made to vibrate by blowing on it. In the Hornbostel-Sachs classification of 1914 by Erich Moritz von Hornbostel and Curt Sachs this term is used for all musical instruments whose sound is produced by tightly stretched membranes.

The sound produced when struck depends on the construction of the membranophone and can either produce a clearly audible fundamental tone or a rather diffuse mixture of different frequencies. Membranophones are drums that can produce certain pitches. These include kettle drums such as the timpani and the tabla as well as some tubular drums such as hourglass drums in Africa or India. Octoban (open bottom cylinder drums) and tabla tarang (kettle drums) are examples of melodic sets of several drums with different pitches.

In instrumentology, percussion instruments are divided into membranophones (Fellklinger) and idiophones (self-strikers). This distinction did not exist in the European Middle Ages. In 1880 Victor Charles Mahillon introduced the classification of musical instruments in 1880.

The classification of membranophones at a glance

The variety of drums is determined by different categories and classifications. Drums can be divided into frame drums, tubular drums and kettle drums according to the shape of the resonating body.

Frame drums

Frame drums are characterized by a flat frame, which is usually covered with a skin on one side, more rarely on both sides, whereby the frame height according to Hornbostel-Sachs corresponds at most to the skin radius. This clear distinction distinguishes frame drums from cylinder drums, although the transitions are fluid. The classification of flat drums is possible up to the frame height of the skin diameter.

The frame can be circular, rectangular or otherwise shaped. The sound is produced by striking the membrane, sometimes also the frame, with the hand, fingers or a mallet. Some of these membranophones can have additional idiophones such as jingles, cymbals or bells on the frame, which extend their sound palette.

List of frame drums

Adufe
Bodhran
Therefore
Daira
Gumber
Kanjira
Pandeiro
Parai
Ravanne
Rebana
Riq
Shaman drum
Tamborim
Tambourine
Tar

Tube drums

A tubular drum is a drum with a tubular body that is beaten directly. The body can be covered with a membrane on one or both sides. If the body is covered on one side, the underside remains open.

There are different types of tubular drums, such as cylindrical drums, which have the same diameter along their entire length, or barrel drums, where the body is bulbous and curves outwards in the middle. There are different types of drums. One variant is double cone drums, which have a larger central diameter and where the body tapers straight outwards on both sides from a bend in the middle. Hourglass drums are waisted and cone drums have membranes of significantly different sizes and form a truncated cone. Beaker drums are single-sided and have a broad upper part and a slimmer extension.

Standing drums are large drums that stand on the floor and are played. There are two other types of drums: Frame drums and kettle drums.

Cylinder drums

Cylinder drums differ from frame drums in that their frame height generally corresponds to the diaphragm radius. This classification, based on practical considerations, applies to most instruments. The Hornbostel-Sachs classification system makes an exception for cylindrical military drums and also classifies models with a lower frame height as cylindrical drums. The term shallow drum refers to a format between the cylindrical and frame drum in which the shell height corresponds at most to the head diameter.

Cylindrical drums, such as the tomtom used in modern drum sets, the snare drum and the bass drum, are made from bent and glued laminated wood panels (sometimes also from plastic) or traditionally from a hollowed-out section of trunk. The clear cylindrical shape is rather rare and is found, for example, in the large Turkish military drum Davul and its Balkan variant Tapan. Even if these could be considered frame drums due to their ratio of height to diameter, they are classified as cylindrical drums due to their origin. Cylinder drums include instruments that are either widespread in various regions or only known locally.

List of cylinder drums

Alfaia
Caixa
Chande
Chenda
Dammam
Doli
Dunun
Lambeg drum
Pambai
Tabor
Tapan
T’bol
Yak bera

Barrel drums

Barrel drums are carved from a block of wood or molded from plastic. They are known in large numbers. The two outer diameters can be of different sizes. This results in two pitches. The round-bellied barrel drums include the South American, single-headed conga:

List of barrel drums

Atsimevu
Buk
Conga
Dhimay
Dhol
Dholak
Dholki
Ghoema
Kendang
Negarite
Taiko
Tavil

Double cone drums

Drums with a double cone have a larger diameter in the middle, the body tapers in a more or less straight line to the ends. Indian double-cone drums in particular, which are played in a horizontal position, have such a clearly visible bend in the middle:

List of double cone drums

Khol
Maddale
Mridangam
Pakhawaj
Pashchima
Pung

Hourglass drums

The middle diameter is smaller than the two end diameters. Some African speaking drums, where the string tension can be changed while playing, have the shape of an hourglass. In Asia, this drum shape is often attributed a religious significance. The damaru, which is played in India and in Tibetan music, is one of the attributes of Shiva and other gods in Indian mythology, and the idakka, which is played in the temple music of Kerala, is revered accordingly.the middle diameter is smaller than the two end diameters. Some African talking drums, where the string tension can be changed while playing, have the shape of an hourglass.

In Asia, this drum form is often attributed a religious significance. The damaru, which is played in India and in Tibetan music, is one of the attributes of Shiva and other gods in Indian mythology, and the idakka, which is played in the temple music of Kerala, is revered accordingly.

List of hourglass drums

Batá drum
Daunr
Dhadd
Hurka
Janggu
Jiegu
Kalangu
Kundu
Timila

Cone drums

The diameters of the two sides are very different. The body has the shape of a truncated cone, which is almost straight in the longitudinal direction.

List of cone drums

Samel

Cup drums

The body of the drum is cauldron-shaped or cylindrical and merges into a tapered lower section. Beaker drums are single-headed and either have a closed body base or are open to the foot end. They are often held between the knees or clamped horizontally under the arm and beaten with both hands. The very large types are fitted with a base plate that allows them to be placed on the floor.

List of cup drums

Bekiviro
Dabakan
Darbuka
Djembé
Ozi
Tombac
Zerbaghali

Boiler drums

Kettle drums are single-headed membranophones with a closed, often semi-circular body on the underside. They are played both by hand and with mallets and can be used individually or in pairs. The spectrum of kettle drums ranges from the timpani of European art music to the naqqaras of the Arab and Central Asian regions and the Indian tabla. The oldest known kettle drum, the lilissu, dates back to ancient Babylonian times and has an impressive bronze body. An exceptionally large 13th century kettle drum was the kūrgā of the Mongols, while the first Ottoman kettle drum, the kútsá, was carried in parades on elephants and camels under Osman I in the 14th century.

Deep kettle drums have a deep, round body, while flat kettle drums have a bowl-shaped body. All other drum types are either open at the bottom like the darabuka beaker drums or covered with skin on both sides like most tubular drums. A rare borderline case is the sahfa stick drum from Yemen, which lies between the flat, open-bottomed frame drum and the kettle drum. The mizhavu from South India forms a transition between the kettle drum and the percussion idiophone and is characterized by a large round copper pot with a tiny membrane that is struck with the hands.

List of boiler drums

Damaha
Damau
Dhamsa
Dhanki
Diplipito
Duggi
Ghumat
Cult run
Nafa
Nagra
Timpani
Rebana
Tamattama
Tasa
T’bol
Turburi

A further subdivision is made according to function, with drums being classified as ceremonial drums, message drums or dance drums. The way they are played can also justify a distinction, e.g. percussion drums, friction drums and plucked drums.

One historical exception is the earth drum, which does not fit into any of the above categories. As the original form of percussion drum, it is characterized by a membrane made of freely stretched animal skin. This complex classification gives the drums a multifaceted role in different musical contexts and applications.

Sound generation with membranophones

The physical principles of sound generation in membranophones, also known as drums, are largely known, but the exact relationship between individual physical effects and the sound image has not yet been fully clarified. There is a parallel between the behavior of loudspeakers and drums. The drum body influences the membrane vibrations and the sound radiation in a similar way to the housing of a loudspeaker, but has no active function as a sound source.

The suspension of the drum membrane on the body distinguishes membranophones from loudspeakers. This results in various forms of vibration such as radial, partial and concentric vibrations, which contribute to the desired sound image. These vibrations are desirable in drumheads and are influenced by various parameters such as material thicknesses, coatings, constructions, damping rings and striking techniques.

A closed drum behaves similarly to a closed loudspeaker box, while open drums influence the sound depending on the body shape. A flat design amplifies low tones through acoustic short-circuiting, while resonance heads use physical effects similar to a bass reflex box to amplify a low fundamental tone.

The complex analysis of the vibration behavior using the timpani as an example shows the variety of physical phenomena in membranophones.