Tubular Gamitadera with membrane

Virtual Research Institute Tlapitzcalzin.


Gamitaderas with lateral hole, of toasted bamboo and cane

(Consulting document)
First version, November 13, 2003.

Key word: aerophone with membrane, tubular Gamitadera, Kazoo, Kazuu, Mirliton, blown, of wind or breath membranophone, game caller.

Introduction.

The object of this article is to analyze experimental models of the so called tubular Gamitaderas with membrane. It is believed that in Ancient Mexico existed aerophones of this type, which were used to call animals generating garbled, nasal or buzzing sounds similar to those produced by reed instruments but with additional acoustical possibilities. These membranes and their sonorous effects were used an appreciated in other continents like Africa and Asia. A similar tubular aerophone without tonal holes is called Kazoo, Kazuu or Mirliton and its industrialized copies in metal or plastic have been patented and commercialized in the USA. Similarly to what has been done to other ancient aerophones like the transverse globular clay design similar to the Niuńe (Mixteca), which was adapted to the modern music and was called ocarina in Italy and the bucal Ehekachiktli, that now is used to call and control shepper dogs in several countries.


Top view of a plastic's industrialized Kazoo, 12 cm long.
(The hole and membrane are shown)

The Kazoo can be played as a small trumpet, exciting it with the lip's vibration and it has been used in Jazz imitating a small saxophone, but it can produce more complex sounds with ancient ways of excitation and operation like those of the Gamitadera. The modern Kazoo is used also as a toy.

The ancient blown membrane without tonal holes is still being made and played in several countries like the one shown here from Spain, made from a hollowed piece of cane to which one end has been covered with a smoking paper membrane or a wet onion skin, perforated at the center and tied with a cord, even at the present time the membrane can be a plastic one.

Similar aerophones are still being made in our continent> in Panama they are being made as Gamitaderas that generates sounds like little deer's' cries.

In Mexico and other zones of America were used similar aerophones with or without lateral tonal hole to call animals, which could operate like the Kazoo or like the whistles used by balloon vendors' whistles (and like the one from Spain). In the balloon vendors' whistles the membrane tied to one end has a small cut on one side and is exited by blowing or sucking air trough the tube to generate the sounds by forcing the flow of air trough the membrane cut and making it to vibrate.


Gamitadera with latex balloon membrane with a cut and tied with a rubber band.
(The lateral cut of the balloon membrane is shown)

There are other aerophones that have been called Gamitaderas like those ones made of bones from Michoacan State, which were mentioned by Otto Schondube, Guillermo Contreras and Jorge Dájer, and are commented in the study of bucal Ehekachiktli but their structure, way of operation and sounds are different. Dajer commented about other Gamitaderas, which were collected by Raul Hellmer, but their characteristics have not been made available to the public. In other study the extraordinary Olmec Gamitadera of clay from the Xalapa museum is virtually analyzed.

Jesús Mora has commented that in his native Guerrero State similar Gamitaderas were used with vat's wings membrane and he is going to try to find any one is still around that knows how to make them.

In the Kazoo type aerophones, the membrane tied to the extreme of the tube has no aperture and the no air is blown through it, it is exited from the opposite end of the tube or from a lateral hole of the tube with sounds generated vocal cords or by the lips. In the Kazoo or Mirlitón the membrane can be fixed in a small tube or hole made over the resonating tube, as in the case of the ones that have been industrialized and the experimenta clay flute with membrane analyzed in other study.

Experienced handy operators have been able to imitate animal sounds, like Jaguars, deers, monkeys, etc., with vibrations generated and modulated with the vocal tract and other resonators like the hands or using canes, gourds, etc., such as those now being used in Brazil and Africa, but usually in these cases the sonorous power in not high..

In the literature about ancient artifacts no Gamitaderas have been found with this type of membrane, possibly because their materials were degraded, and for that reason it is not possible to use archaeological information. In this case, neither the technical musical analysis is of any use, because the Gamitaderas operated in their complex way did not generate musical sounds according to their actual concept. Not knowing acoustical analysis of these type of aerophones, with membrane, some experimental exercises were made.

Experimental models.

Due to the fact that the most complex operation ways of Gamitaderas have not been mathematically modeled, which is considered difficult to do, several physical models were made to experimentally analyze their characteristics. Several experimental models were made like the flute with yellow flower and it was found that the membrane functions well with different designs and dimensions of tubular and globular aerophones. The membrane can be of several materials industrialized or synthetic like plastic, wax paper, cellophane, latex, etc., with the corresponding variations in timber of the generated sounds. The slightly rigid materials like those that make noise when handled, like those from plastic bags, can generating buzzing sounds. The membrane without a hole or cut can be tied to the tube or secured with bee's wax or tied to the tube and its function is to add the special timber without altering the pitch F0 of the resonating sounds. The low tension of the membrane must be adjusted so it works properly. It must be loose or almost free so it can easily vibrate with the variation of the pressure at resonance of the air inside the tube.

As it happens with some apparently simple ancient aerophones Maya trumpets of Bonampak, it has been seen that the Gamitaderas, even though they do not have tonal holes, can generate a variety of sounds when coupled to other acoustical possibilities like the operator's vocal tract or hands. The tubular Gamitaderas can be excited with complex sounds and not constant in time like those generated by changing the vocal tract configuration and some more intense ones with the phonemes that include vowels. The hands can be used to form a "bell" or additional resonator at tube's exit, which can change its volume and form.

Analysis of the toasted bamboo Gamitadera.

The 16 cm long with a lateral hole bamboo tube used in this exercise is very similar to the virtual study of the extraordinary aerophones of Caral, which are the oldest known in America. Only the plastic membrane was added, which is tied with a nylon cord. The model can generate diverse sound such as the following.


Spectrogram of a simple sound of the bamboo tube with membrane.

It can be seen and heard that the sound is like a buzzing one but its F0 has variations and many harmonics are generated.


Spectrogram of a complex sound.

The sound produced is different is not musical. It has much noise and resembles a cat's roar.

The radiated acoustic power of the Gamitadera's sounds is not very high, but are heard at considerable distances due to the harmonics that they can produce. The highest sonorous intensity of the used model is around 88 - 90 dB (at 1 m and 0 degrees, which is equivalent to a radiated acoustic power of ~ 0.008-0.01 Watts.

It was seen that membranes can function well with different designs and dimensions of tubular and globular aerophones. For example, the membranes function very well with models of the transverse whistles and clay singer birds, which have the most possibilities to generate microtonal sounds, besides the flutes.

The result of the exercise indicates that even the most ancient of our continent models of tubular aerophones with a lateral hole, can operate well with.

If these aerophones with membrane were used in Africa, Asia and America, it indicates that some teachers of their cultures had similar ancient knowledge in the organological-acoustical field and perhaps they had some type of communication.

What is for sure is that the so called Gamitaderas represent one of the most proper and distinctive sonorous choice of the ancient cultures, due to the fact that their use indicates the close relation with the biological beings that they venerated, feared or hunted.