A cajon is a box-shaped percussion instrument that originated in Peru. It looks like a wooden crate or box, and in fact, cajon means “box” or “crate” in Spanish. The cajon is played by slapping the front face with the hands and fingers to produce a wide range of percussive sounds.
One of the most distinct features of the cajon is the large hole cut out of the rear face. This hole serves several important purposes that help define the unique sound and playing technique of the cajon.
Acoustic Properties
The hole in the cajon has a significant effect on the instrument’s acoustic properties and sound projection. The hole allows sound waves produced by slapping the front face to resonate inside the box and then project directly out through the opening. This creates a forward-aimed sound that gives the cajon a strong percussive attack and presence when played in a musical ensemble.
Without the hole, the sound would be more contained within the wooden box itself. There would be less projection and resonance, resulting in a weaker, less defined acoustic voice. The hole allows the player to control dynamics and timbre through slapping technique at different spots on the front face.
Playing Technique
In addition to sound production, the hole is an essential ergonomic element that facilitates the hand slapping technique used to play the cajon. Peruvian cajon playing involves using the bare hands to strike the front face, with the thumb often anchored inside the hole for stability and leverage.
Having the thumb inserted in the hole allows the player to put force behind the other fingers during slap strokes. The hole gives a fixed reference point so players can develop coordination between their hands. Different tones can be produced by slapping the front face near the hole versus further away.
Bass Tone
Inserting the thumb into the hole also allows players to produce a deep bass tone on the cajon. The inward pressure of the thumb changes the internal air pressure within the box, which adds a low frequency element to the sound. Anchoring inside the hole gives stability to dynamically vary this bass tone.
History and Origins
Understanding the historical context in which the cajon originated sheds light on why the rear hole became a standard design element.
The cajon first emerged in Peru in the early 19th century among slave populations who were prohibited from using drums but still wanted to make music. They came up with the simple percussion box that could be disguised as a seat. The hole likely developed from cajones being repurposed from crates and shipping boxes that already had an opening.
Early cajon players realized this hole facilitated good acoustic properties and the percussive playing technique. Cajon makers started intentionally cutting holes in the back as they turned to specialized construction. The hole has remained an essential design feature to this day.
Acoustic Idiophone Classification
The cajon falls under the category of an ‘acoustic idiophone’ – meaning the sound is produced by the instrument itself vibrating, without need for strings, membranes, or additional parts. The hole optimizes the cajon’s ability to act as a hollow percussive idiophone.
Leaving one face open allows the acoustic energy from hand slaps to reverberate inside the chamber and project outward. The specifics of the hole’s size, shape, and placement are acoustic design elements that influence the cajon’s sound and response.
Construction and Structural Integrity
The hole forms an integral part of the cajon’s construction. Cutting an opening into the back face lightens the overall weight of the box and reduces the amount of wood required. This is important for an instrument meant to be portable and played while seated.
The back face needs to have enough continuous surface area and bracing around the hole to maintain structural integrity under the tension of the drumhead-like front face. The specifics of bracing and hole placement prevent cracks from developing over time and use.
The hole itself requires careful cutting, usually with a jigsaw, along with expert craftsmanship to achieve a smoothly sanded edge. This ensures player comfort while maximizing acoustic response. As a critical construction element, the hole needs to achieve ideal function in both design and practice.
Ergonomics and Comfort
In addition to structural integrity, the hole factors importantly into the ergonomics and playing comfort of the cajon. The size and shaping of the hole accommodate the thumb and hand positions used in traditional cajon playing technique.
A comfortable bevel and sanded edge prevent abrasions during extended percussion sessions. The hole’s location aligns properly with hand placement on the front slap face. All these factors taken together allow expressive and dynamic cajon playing to be done comfortably and naturally.
Modern Variations
While the rear hole has long been a standard on cajons, some modern versions explore variations on the traditional hole design or eliminate it entirely.
Multiple Holes
Some contemporary cajons feature two or more holes rather than one. Extra holes can change resonance and sound projection qualities. Side holes radiate sound horizontally rather than just forward. This puts acoustic energy into a room rather than solely toward the audience.
Multiple holes add options, but can sacrifice some focused acoustic power compared to a single, well-placed hole.
No Hole
There are hole-less cajon designs, often called tap boxes. These are simpler to construct but lack the acoustic fortification and ergonomic thumb support the hole provides. Sound resonance exits through cracks rather than an opened chamber.
Tap boxes present an alternative appearing more box-like, though traditional single-hole cajons remain most popular across Peru and globally.
Global Spread
As the cajon gained popularity internationally outside of Peru in the late 20th century, the essential hole has remained a part of export models. Musicians around the world have come to expect the acoustic and ergonomic benefits offered by the signature hole.
Adding a hole – and structurally reinforcing around it – does increase manufacturing costs and complexity. But professional cajon-makers realize this crucial element defines the instrument’s identity and capabilities.
The global spread of the cajon has kept the hole globally standardized as well, with variants like multiple holes and no holes remaining rarities outside Peru.
Cajon-centric Music
With the cajon’s use proliferating in genres from flamenco to folk rock, a growing canon of cajon-centric music relies on the hole’s acoustic contributions. The instrument is often recorded using microphones aimed directly into the back hole to best capture its rich sonic complexity.
Music written specifically for the cajon takes advantage of the slap and bass tone techniques afforded by the hole to best accentuate the instrument’s rhythmic potential.
Cultural Significance
Beyond physical construction and playing technique, the cajon’s hole holds cultural meaning for Peruvian musicians and those who have adopted it abroad.
The hole ties the cajon directly back to its origins born out of slavery and repression, turning discarded crates into musical opportunity. It represents the resourcefulness and creativity that birthed the instrument itself.
Peruvians see the cajon hole as part of their unique cultural heritage and national musical identity. The instrument could lose authenticity if the hole’s familiar acoustic and ergonomic purposes were lost.
Customization
While generally standardized, players do customize their cajon’s hole to some degree as a way of personal artistic expression. Decorative or colored tape around the hole’s edges, customized shape and bracing, or added brightness from internal bottlecaps all allow musicians to make the instrument their own.
The cultural significance of the cajon hole gives it an important flexibility while retaining its core identty.
Conclusion
In conclusion, the signature hole found on the back face of a cajon serves multiple integrated purposes that give the instrument its characteristic sound, technique, history, and cultural meaning. The hole arose organically out of necessity and limitations, but through time and refinement has become a standardized element across cajon construction and music.
Structurally, acoustically, ergonomically, and culturally, the cajon hole forms an indispensable part of the instrument’s identity. Musicians and makers require it to achieve the proper cajon punch, tone, projection, and authenticity. The hole connects players directly to centuries of musical tradition rooted in both adversity and ingenuity.
Far from being a random design choice or construction shortcut, the cajon hole developed alongside the instrument itself as an essential physical and cultural element. It continues to define the cajon’s voice and enable expressive hand percussion wherever cajons are played worldwide.
