PHYS341/2024/Project1

Boxed Didjeridu

The didjeridu (did-jer-ee-doo) is a wind instrument played using circular breathing to vibrate one's lips and create a continuous drone. This instrument can be traced back to the Aboriginal people of northern Australia and is now a globally used instrument. In the Yolnu languages of the indigenous people of northeast Arnhem Land, the didjeridu is called the yidaki or mandapul.

History

Anthropologist W. Lloyd Warner commenced field research at Milingimbi, and later published “A Black Civilization: A Social Study of an Aboriginal Tribe”, the first ethnographic study of an Australian Aboriginal tribe. Mention is made of the Iraki (another name for the didjeridu), a “trumpet about four feet long”.

The didjeridu, a wind instrument indigenous to Australia, holds a rich cultural history deeply rooted in the traditions of Aboriginal peoples. While some believe it to be one of the oldest wind instruments in the world, there are no reliable sources on the exact age of the didjeridu. Archeologists have been able to trace the didjeridu back to rock art paintings dating back 1,000-2,000 years ago in the Kakadu region. The first painting was found in Ginga Wardelirrhmeng, situated on the northern periphery of the Arnhem Land plateau during the freshwater period, a distinct rock painting illustrates a scene wherein a didjeridu player and two song-men engage in an Ubarr ceremony, marking a tradition that commenced approximately 1500 years ago. However, artifacts like this one suggest a long-standing presence within Aboriginal societies, where the didjeridu holds sacred and practical importance. Furthermore, oral traditions passed down through generations reinforce its integral role in Aboriginal culture.

Etiology

The Aboriginal peoples of northern Australia have bestowed numerous names upon the instrument, none of which closely resemble the term "didjeridu." Advocates within the didjeridu community, scholars, and Indigenous individuals encourage the use of local language names for this iconic instrument. One widely recognized name is Yiḏaki, which is particularly associated with a specific type crafted and utilized by the Yolngu peoples of northeast Arnhem Land. However, in recent years, some Yolngu individuals have adopted the term mandapul, as a mark of respect following the passing of a Manggalili man whose name bore similarities to Yiḏaki.

In west Arnhem Land, the instrument is commonly referred to as a mako, a term popularized by the renowned player David Blanasi, a Bininj man from the Kunwinjku language group, who played a pivotal role in elevating the didgeridoo to global recognition. Nonetheless, the mako possesses slight distinctions from the Yiḏaki, typically being shorter and producing a somewhat different timbre—a fuller and richer sound albeit lacking the distinct "overtone" note.

The didgeridoo boasts over 45 regional names, some of which hint at its original construction from bamboo, including bambu, bombo, kambu, and pampu, which persist in the lingua franca among certain Aboriginal communities. These diverse names reflect the instrument's profound cultural significance and the myriad traditions surrounding its use across different Indigenous groups in Australia.

Cultural Significance

‘Tribal Music of Australia’ LP, the first commercially available recording of the didjeridu and field recorded by A. P. Elkin in Arnhem Land, released by Folkway Records.

Historically, the didjeridu served as both an accompaniment to ceremonial rituals, including dancing and singing, and as a means of solo expression or leisure among Indigenous communities. Among the Aboriginal peoples of northern Australia, the yidaki remains integral to cultural ceremonies, where it accompanies singers and dancers. For the Yolngu people specifically, the yidaki holds profound significance within their physical and cultural landscape, embodying connections to their land, kinship structures, language, and spiritual beliefs. Rooted in Yolngu Law, the instrument is central to ceremonial practices encompassing song, dance, visual arts, and storytelling, reflecting the rich tapestry of their cultural heritage.

During ceremonies, pair sticks, also known as clapsticks (referred to as bilma or bimla by certain traditional groups), establish rhythmic beats that guide the songs. These intricate rhythms, passed down through generations, synchronize with the didjeridu drone, creating a harmonious blend of sound. Within the Wangga genre, song-men typically initiate vocals before introducing clapsticks to accompany the rhythmic patterns set by the didjeridu, showcasing the interplay between vocal expression, percussive elements, and the mesmerizing tones of the instrument.

Didjeridu: Tradition and Gender

Traditionally, the playing of the didjeridu and singing during ceremonial events was strictly reserved for men within Aboriginal communities, with discouragement of women's participation. While women traditionally refrained from playing the didjeridu in ceremonial contexts, there was no formal prohibition in informal settings according to Dreaming Law. Historical recordings, such as Alice Marshall Moyle's 1966 documentation of Mara woman Jemima Wimalu playing the didjeridu proficiently, demonstrate instances where women have engaged with the instrument.

However, while there may be no explicit prohibition in the didjeridu's native regions, certain Indigenous communities, especially in the Southeast of Australia, do not alloy female players. The taboo against women playing the didjeridu is widespread among non-Aboriginal individuals and some Indigenous groups in Southern Australia, where it is viewed as cultural appropriation and even "cultural theft." Ethnomusicologists suggest that the perpetuation of these beliefs, alongside other misconceptions, can be attributed to commercial agendas and marketing strategies, particularly evident in the portrayal of the didjeridu as a spiritual instrument in New Age music recordings.

Construction and Measurements

Typically cylindrical or conical in shape, a didjeridu varies in length from 1 to 3 meters (3 to 10 feet), with the average falling around 1.2 meters (4 feet). The instrument's length correlates with its pitch: longer didjeridus produce lower tones, while those with flared ends generate higher pitches compared to unflared counterparts of the same length.

Categorized as a wind instrument, the didjeridu bears resemblance to a straight trumpet but is crafted entirely from wood. It is sometimes referred to as a dronepipe, owing to its characteristic sustained drone sound.

Traditional didjeridus are typically crafted from hardwood, with a preference for various species of eucalyptus found in northern and central regions of Australia. Generally, the main trunk of the chosen tree is harvested for this purpose, although sometimes a substantial branch may suffice. Skilled didjeridu artisans search for live trees exhibiting signs of termite activity, as these insects selectively hollow out the dead heartwood while avoiding the living sapwood due to its natural insect-repelling properties.

Finding the perfect hollowed tree involves a combination of techniques, including understanding the landscape and patterns of termite activity. A distinctive tapping or knocking test is also employed, where the bark is peeled back, and a tool or fingernail is gently struck against the wood to gauge the resonance of the hollow space within. Once a suitable tree is identified, it is carefully felled, cleaned out, stripped of bark, and trimmed to size, resulting in the creation of a raw didjeridu. Artisans then shape the exterior before potentially applying a rim of beeswax to the mouthpiece end, completing the transformation into a functional musical instrument.

Acoustics of the Traditional Didjeridu

A termite-bored didjeridu.

Playing the didjeridu begins with creating a vibrating sound of the lips to produce the fundamental drone. Advanced techniques involve mastering circular breathing, where the player inhales through the nose while simultaneously using cheek muscles to compress and release stored air from the mouth. Through this method, skilled players can continuously replenish lung air and sustain a note indefinitely with practice. Circular breathing enhances the instrument's capabilities, allowing for prolonged and seamless performances.

A termite-bored didjeridu typically exhibits an irregular shape, often widening towards its lower end. This unique shape leads to non-harmonically spaced resonances, unlike the harmonically spaced resonances found in cylindrical plastic pipes, where frequencies fall in ratios like 1:3:5, similar to the major chord in the Western chromatic scale. The didjeridu's second resonance, sounded by overblowing, tends to be approximately an 11th higher than the fundamental frequency, represented by a frequency ratio of 8:3.

The vibrations generated by the player's lips follow harmonic patterns such as 1:2:3, but the didjeridu's non-harmonic resonance spacing means these harmonics aren't systematically reinforced by the instrument's resonances, unlike in Western wind instruments. Instead, strong resonances from the player's vocal tract heavily influence the instrument's timbre. At certain frequencies, determined by the position of the player's tongue, vocal tract resonances can impede airflow into the instrument. Frequencies unaffected by this inhibition produce formants in the output sound, contributing significantly to the didjeridu's distinctive timbre, especially as they vary during circular breathing.

Additional nuances in the didjeridu's sound are achieved by incorporating vocalizations into the drone. These vocalizations often mimic sounds of Australian animals like the dingo or kookaburra. Players produce these sounds by simultaneously using their vocal folds to emulate animal noises while maintaining airflow through the instrument. The resulting sounds range from high-pitched to lower tones, involving interactions between lip and vocal fold vibrations. Incorporating vocalizations adds depth and complexity to the instrument's performance.

The Didjibox (Non-Traditional Didjeridus)

A wooden micro-didjibox. This version of a modern didjeridu takes the traditional tube and coils it into a snaking shape to fit it compactly into the box. This particular version is especially small, raising its fundamental frequency significantly in comparison with a traditional didjeridu.

Non-traditional didjeridus embrace a diverse range of materials including native or non-native hardwoods, glass, fiberglass, metal, agave, clay, resin, PVC piping, and even carbon fiber. These instruments are typically crafted by splitting, hollowing, and rejoining materials, resulting in a variety of shapes and sizes. They often feature an upper inside diameter of approximately 3 centimeters (1.2 inches), tapering down to a bell end ranging from 5 to 20 centimeters (2 to 8 inches) in diameter, with the overall length tailored to achieve the desired musical key. The end of the didjeridu can be shaped and smoothed to form a comfortable mouthpiece, or alternatively, an additional mouthpiece can be fashioned from various materials such as rubber, a rubber stopper with a hole, or beeswax.

Innovations in didjeridu design emerged in the late 20th century, introducing non-traditional materials and shapes. While recognized as musical innovations by scholars, these modern designs have stirred considerable debate among indigenous practitioners and non-indigenous individuals regarding their aesthetic, ethical, and legal implications. This ongoing discourse reflects the evolving nature of the didjeridu as it intersects with contemporary craftsmanship and cultural sensitivities.

Marko Johnson conceived the original "Didjbox" in 1995. The inaugural production line of the didjibox debuted in 1999. Since its inception, an array of iterations have emerged, such as the traveler box, obelisk box, didjiflute, meditator, and mindblower. The didjibox boasts a monotonal quality and is crafted in the specific keys of C, D, and E.

Acoustics of the Didjibox

The time graph of the modified didjeridu shows a periodic repetition of frequencies.

When considering our didjibox's physics, we will examine the boxed design. Introducing a didjeridu with a box-shaped design, where the typically cylindrical tube becomes winding, alters the instrument's acoustic properties and physics of sound production.

Spectral graph for the boxed dijeridu shows that fundamental frequency is 195Hz, with harmonics that seem close to consistent with f, 2f, 4f, 6f ...

Firstly, the change in shape would influence the resonance frequencies of the instrument. In a traditional cylindrical didjeridu, the resonances occur at frequencies that are not harmonically spaced due to its irregular shape. However, with a box-shaped design, the resonances follow a more predictable pattern, akin to those found in cylindrical plastic pipes, where frequencies fall in ratios such as 2:4:6. The box shape introduces more organized harmonic resonances, altering the overall timbre and tonal quality of the instrument to create a slightly warmer sound.

In a traditional didjeridu, the body of the instrument is cylindrical and airflow moves relatively smoothly along the straight path of the tube. However, in a didjibox, airflow encounters more turbulence and resistance as it navigates the winding passages. Air molecules knock against more surfaces and are redirected more often. This impacts the player's ability to control airflow and sustain notes, and raises the fundamental frequency of the sound.

The shape of the vocal tract resonances are influenced by the box-shaped design. In a traditional didjeridu, the player's vocal tract resonances interact with the instrument's acoustic properties to produce characteristic formants in the output sound. With a didjibox, the positioning and distribution of these resonances differ, leading to variations in the timbre and overall sound of the instrument.

Didjibox Play Mechanics

Mouthpiece of the modified modern didjeridu. This mouthpiece is a circular hole, quickly cut in half by a ledge about 3 cm into the box.

The didjibox is a wind instrument distinguished by its mouthpiece and body, both possessing natural frequencies responsive to the air pressure generated by the player's breath. The player's lips serve as the double reed, vibrating to create sound waves as air is forced through them.

The mouthpiece of the didjibox features a circular opening with a small piece of wood positioned about 3 cm down. This is where oscillations of air are created. Similarly to a flute, the player's lips act as a reed and vibrate as the player creates an 'airjet', or constant stream of air. This 'airjet' oscillates up and down over the wooden piece inside the didjibox to match the frequency of the natural fundamental in the body of the instrument. This fluctuation creates the oscillation necessary to make sound. This design contrasts with traditional didjeridus, where airflow typically travels in a single direction through the cylinder.

In the didjibox, however, some air molecules rebound towards the opening, particularly at the curves of the tube. These airflow dynamics lead to frequency locking, where the resonant frequencies of the instrument align with those of the air column, resulting in sustained, harmonious tones.