Implications of Obscured Original Sound Sources on the Authenticity of Electroacoustic Music

The way that we experience and respond to sound art and music has changed rapidly in recent decades. The technologies and environments surrounding these experiences have been both the cause and response to such change.

Electroacoustic music is a genre of music that involves the manipulation and transformation of recorded sounds, as well as the creation of new sounds through any electronic means. This type of music combines traditional musical instruments and techniques with electronic technology, most commonly; synthesisers, samplers, and digital signal processing, to create unique and experimental compositions.

In electroacoustic music, sounds can be recorded from the natural environment, manipulated to create new sounds or altered through electronic processes, and combined with other sounds to create a final composition. The genre has its roots in the early experiments with electronic music in the mid-20th century and has since expanded to include a wide variety of styles and techniques.These can range from purely electronic pieces to works that incorporate acoustic instruments, live performance, and multimedia elements, often used in film and video game soundtracks, as well as in avant-garde and experimental music contexts. The genre continues to evolve as new technologies and techniques are developed, making it an innovative field for composers and performers. 

The perception and interpretation of sound art and music have undergone significant transformations in recent decades, spurred by advancements in technology and evolving environments as well as changing social concerns within arts communities. Electroacoustic music in particular, has expanded the realm of sonic possibilities, encompassing a vast array of sounds from everyday life. Listeners are often confronted with unfamiliar sonic shapes and qualities that are not recognisably traditional associations with physical sound production. This departure from conventional musical articulations, such as instrument timbres, vocal expressions, and rhythmic structures, engenders a profound reevaluation of the concept of authenticity in electroacoustic music. 

‘The art of music is no longer limited to sounding models of instruments and voices. Electroacoustic music opens access to all sounds, a bewildering sonic array ranging from the real to the surreal and beyond. For listeners, the traditional links with physical sound-making are frequently ruptured; electroacoustic sound-shapes and qualities frequently do not indicate known sources and causes. Gone are the familiar articulations of instruments and vocal utterance: gone is the stability of note and interval: gone too is the reference of beat and metre.’ Smalley, D. (1997)

The word that repeats here is ‘gone’. This emphatic repetition suggests that what was once the fundamental structure to our understanding of authentic sound, has itself ‘gone’. Subsequently, this sense of loss has precedence over our understanding of where the origin of a work of art lies, particularly concerning the technology used in the creation of sound art.

Human beings are naturally drawn to novelty, yet seek comfort in the familiar. Thus, for a person to recognize a structure as music, it often requires repeated exposure or sufficient acclimatisation to the structural references embedded within the sounds. With access to archives of pre recorded sounds encompassing a wide range of sources such as instruments, field recordings, and soundscapes, individuals utilising sound as an artistic medium have at their disposal nearly all audible sounds known to humanity. We are attracted to what is new and we are most comfortab;e where we are familiar. If recognising something as music has to do with whether a person can perceive a structure as familiar, then a sound can not be music until we hear it enough to become a memory, accustomed to its contextual references.

‘Even the most perfect reproduction of a work of art is lacking in one element: it’s presence in time and space, its unique existence at the place where it happens to be. This includes the changes which it may have suffered in physical condition over the years as well as the various changes in its ownership.’ W, Benjamin. (1968)

We are left in this age, with a loss of confidence in assumption.We are so much more connected and so empowered by our increasing abilities to create and reproduce quickly that we can no longer be sure of our own senses. In the realm of electroacoustic music, the technical detachment between sound and its original source necessitates the development of novel compositional listening strategies. Listening becomes a symbolic mode where sounds function as signs and signifiers, demanding that the audience's attention be focused on the inherent qualities and characteristics of the sound itself. The abundance of materials and archives of previous musical artworks further complicates matters, as the historical context and understanding with which they were created become further distorted by the rapid production and temporal degradation of physical archives. Consequently, the established tools of musical comprehension must swiftly adapt. Listeners face the increasing difficulty of perceiving the intricate layers embedded within sounds, leading to the emergence of sound as symbols, signs, and signifiers, acting as communicators of concepts within the work. Sounds within sounds.

An artist may intentionally conceal or obscure a piece's material sound source to draw attention to the intended conceptual or perceptual aspects of the work. However, this raises questions about the historical significance of the sound as the origin of a source. Although audiences of electronic sonic art may struggle to identify a sound's original source, they cannot dissociate themselves entirely from real-world references, as these sources persist beneath layers of technology and environmental influences, leaving traces. What, then, becomes of the relationship between the perception of the original sound source and the perception of real-world models? If the conceptual, social, or institutional dimensions of sounds can only be understood based on their perceptual properties, how do these interactions disrupt the familiar rules of listening, which rely on familiarity and recognition?

Transformation & Impact of Developing Technologies

The rapid advancement of easily accessible technologies has revolutionised the landscape for electroacoustic musicians, offering unprecedented resources and possibilities. Technology has not only become a subject of investigation and source material for artists but also a tool that aids musicians and enriches artistic creations. Consequently, every facet of electroacoustic music, from idea generation to work realisation and audience experience, has been profoundly impacted. Musicians now possess the ability to sculpt sounds, deconstruct and reconstruct them, and combine and alter them, all with a focus solely on the auditory domain and with only the sense of sound in mind.

‘In live electronic music the technology is used to generate, transform or trigger sounds (or a combination of) in the act of performance; this may include generating sound with voices and traditional instruments, electroacoustic instruments, or other devices and controls linked to computer-based systems. Usually depending on loudspeaker transmission, electroacoustic work can combine acousmatic and live elements.’ S. Emmerson, D, Smalley (1994)

What physical attributes of electroacoustic music are caused by the nature of technologies?

1. Spatialisation: Electroacoustic music often employs techniques to manipulate the spatial distribution of sound. Technologies such as surround sound systems, multi-channel audio setups, and ambisonics enable composers to create immersive and spatially dynamic listening experiences. By controlling the placement, movement, and spatial characteristics of sound sources, electroacoustic music can achieve a three-dimensional quality that goes beyond traditional stereo recordings.

2. Timbral Manipulation: Through synthesis techniques, effects processors, and digital signal processing algorithms, electroacoustic music can transform and reshape the sonic characteristics of recorded sounds or synthesised tones. This allows for the creation of unique and otherworldly timbres that would be difficult or impossible to achieve using acoustic instruments alone.

3. Sampling and Sound Collage: The use of sampling technology in electroacoustic music allows composers to incorporate pre-recorded sounds from various sources into their compositions. This enables the creation of intricate sound collages, where different sounds and snippets are combined, layered, and juxtaposed to create complex sonic textures and narratives. Technologies like samplers, loopers, and granular synthesis provide the means to manipulate and arrange sampled materials.

4. Real-time Interactivity: Many electroacoustic compositions involve real-time interaction between performers and technology. This can be achieved through the use of controllers, sensors, and computer software that respond to the gestures and actions of the performers. Real-time processing allows for improvisation, live manipulation of sound parameters, and the creation of dynamic and responsive musical experiences.

5. Non-linear Composition and Editing: Digital technologies facilitate non-linear approaches to composition and editing in electroacoustic music. Composers can work with sound materials in a non-linear fashion, manipulating, arranging, and structuring them in a flexible and iterative manner. Digital audio workstations (DAWs) and computer-based software provide precise control over editing, sequencing, and arrangement of sound elements, allowing for experimentation and exploration of compositional possibilities.

As technology develops, so do our listening habits. These resources have shifted the emphasis in electroacoustic music away from traditional aspects such as scores, rhythm, movement, harmony, and melody. Instead, the focus lies on the gestural and textural qualities inherent within the sounds themselves, irrespective of their original sources. Consequently, listeners are often unable to pinpoint the exact origins of the sounds they hear. Luigi Russolo (1913) manifesto "The Art of Noise," proposed the need for a new musical practice that transcended the barriers of sound sources. For the purposes of this essay, everyday sounds will be referred to as "real-world" sounds, acknowledging their potential incorporation and utilisation in live performances. In 1913, there were no recordable technologies available that could integrate real-world sounds into live performances, prompting Russolo to create noise-generating machines called Intonarumori and assemble a noise orchestra to play them. Russolo opened up new experiential possibilities for listeners and established sound itself as a legitimate artistic and musical source.

As technology continued to evolve, composers further explored the integration of real-world sources in music and sound art. The advent of multi-channel devices played a particularly crucial role in this exploration. Pierre Schaeffer, considered one of the pioneers of electroacoustic music, experimented with recording technologies in his work. In his piece "Etude Aux Chemins De Fer," he recorded trains on location and then edited and combined the recordings in a studio to create a sound composition that, while clearly composed, defied the conventional understanding of music held by his audience in 1948.

For audiences of electroacoustic music, the shift in the primary sounds employed by musicians and artists necessitated a corresponding shift in their listening focus. Whether it originated from the real world, was electronically produced, edited, or unedited, the audience could no longer rely on assumptions. Nonetheless, the source remains embedded within the historical context of the sound itself.

The Impact of Sampling Technology on the Evolution of the Musical Landscape

Sampling technology has had a profound impact on the musical landscape, revolutionising the way music is created, produced, and consumed. Democratisation of music production has made music production widely more accessible to a larger range of artists and listeners. It allows musicians to incorporate pre-recorded sounds from various sources into their compositions without the need for extensive instrumental or technical skills. This has empowered artists to create music in their own homes or studios, bypassing the need for expensive recording equipment or large production teams.

The creation of new musical genres and styles has been made possible by sampling technologies at a facer pace than before. Artists have used samples creatively to blend different genres, experiment with unconventional sound combinations, and create unique sonic textures. Genres like hip-hop, electronic music, and various forms of remix culture have been shaped by the innovative use of sampling technology, and has also enabled musicians to incorporate elements of existing recordings, whether they are from popular songs, historical recordings, or obscure sources. This has given rise to cultural and artistic sampling, where artists reference and reinterpret musical traditions, historical events, speeches, and other cultural artifacts. It has allowed for a new level of intertextuality and dialogue with the past within contemporary music.

Sampling technology has facilitated the creation of intricate sound collages and complex sonic landscapes. Artists can layer and manipulate multiple samples, combine different textures and timbres, and create rich and immersive sonic environments. This has expanded the possibilities for sound design in film, television, and multimedia projects, enhancing the storytelling and emotional impact of audiovisual experiences.

Another social issue that has arisen is through copyright and legal challenges. The widespread use of sampling has raised complex legal and copyright issues. As sampling often involves using copyrighted material without permission, it has sparked debates and legal battles regarding intellectual property rights. These challenges have influenced the development of copyright laws, fair use guidelines, and licensing practices, shaping the legal framework for sampling and its impact on the music industry. Sampling technology has provided a platform for artists to engage in cultural commentary and critique. By appropriating and re - contextualising existing recordings, artists can subvert or challenge societal norms, political ideologies, and commercial practices. Sampling has become a tool for artists to express their perspectives, challenge authority, and create dialogue through their music.

Instrumentation

One of the most notable transformations resulting from technology in electroacoustic performances is the shift in instrumentation. Originally designed to assist musicians/artists, various technologies have now evolved into instruments in their own right. Increasingly, artists are creating their own instruments and referring to the technology they employ as instruments within their ensembles. This trend has led to the emergence of non-traditional instruments, repurposed analogue electronics, and tools for sound editing such as signal processing and synthesis.

While most musical instruments can be categorised as traditional, such as percussion, simple wind, complex wind, plucked string, and bowed string instruments, the advent of electroacoustic music has brought about dramatic changes to the physical nature of familiar instruments. As a result, audience members can no longer rely on familiarity or preconceived expectations when experiencing these performances.

Although technology brings about vast opportunities, it also possesses limitations. Some artists have turned to hardware solutions amidst the rapid advancement of software. These hardware solutions offer a familiar format and recognisable context that can be modified or adapted. For instance, artists have embraced the revival of old technologies and hardware, including tape recorders, vinyl, turntables, and even circuit bending of previously non-musical hardware.

Software advancements, facilitated by personal computers and programs like Max MSP and PureData, have empowered artists to create their own models and rules that were previously limited or non-existent with pre-existing hardware alone. These technologies have allowed for a more complex yet subtle relationship between human interaction and the physicality of an instrument. Subtlety plays a crucial role for artists seeking to emulate and expand upon existing sound sources. Consequently, the audience becomes further removed from the original or real-world sound source than ever before. The evolving interplay between an instrument's physicality and human interaction can be examined in terms of what remains recognizable from the original sound source and how it is perceived by the audience.

Artist Christian Marclay once remarked that audiences often inquire about the source material, assuming he played certain sounds when he actually did not. 

“Sometimes people will hear something, and they'll ask ‘did you play this?’ when I actually didn’t. It’s interesting that audiences have this need to identify the source material. Once different, unrelated records are combined, they sometimes have the power to trigger the memory of a tune. I don’t consciously make music to trigger memory but it happens naturall. Music has powers in triggering memory, collective memory and private memory. These records often have different sets of references for different people, because most memories are personal and subjective. Whatever happens in their mind is something that I can’t control, I can’t control what they think about what I’m doing. It;s like silent audience participation.” C, Marclay (1998)

Marclay's work involved buying multiple records and manipulating them through slicing, scratching, breaking, bending, and reconstructing to create new sound collages. He performed these collages live using turntables. He also emphasised the importance of incorporating unwanted sounds, such as clicks, pops, surface noise, and scratches, which originated from the deterioration of the records themselves. Rather than rejecting these sounds, Marclay aimed to highlight them, making the audience aware that they were listening to a recording and not live music. By drawing attention to the medium of vinyl, he underscored its significance as the primary means through which people engage with music. Typically, we abstract the medium, but Marclay deemed it essential to emphasise and give voice to this awareness.

Artists like Marclay are increasingly focused on utilizing technology to accentuate and draw attention to the particular qualities of sounds, surpassing the emphasis on representational forms. "Sound quality" refers to the assessment of the accuracy, enjoyability, or intelligibility of audio output from an electronic device. This evaluation can be objective, involving tools that measure the accuracy of sound reproduction, or subjective, relying on human listeners' responses

Environmental Shifts and their Impact on Compositional Resources

The changing environments for sound perception has significant implications for compositional resources, consequently influencing modes of listening that are concerned with sound emission identification. Conventional settings for music/sound consumption provide a basis for manipulating the auditory system by modifying these environments. Listening experiences can vary greatly, ranging from overwhelming immersion to sparsity and disconnection, or absolute nonchalance, for example the rise in ‘elevator music’. In the realm of electroacoustic music, the presentation of the work is crucial, as it cannot exist in isolation but depends on an audience and a performance. Just as changes in technology have influenced the availability of resources, alterations in environments also impact the potential embodiment of sound within a structure.

The rise of concealed sound sources and our innate tendency to relate to real-world models pose challenges to the temporal aspects of electroacoustic music. Sound, as a medium, confines its audience to rely solely on memory for reflection. Even in the present moment, when experiencing sound, one must depend on perceptual abilities to contextualise the auditory stimulus they are experiencing. Sonic properties that guide our attention have become inseparable from the environments they inhabit, which may differ from our historical understanding of music experiences and spatial context.

One way in which the environment directly influences the sound source is through its impact on temporal changes. The incorporation of multi-channel technologies and live performances involving human interaction with instruments and triggers for pre-recorded sound challenges conventional notions of scale and time. Layering of sounds, often accompanied by an array of sound editing effects, results in a convergence of different time scales. The overall duration of a piece may encompass microcosms of pre-determined specified durations. For instance, if layered pre-recorded sounds are utilized, their durations may be dictated by the natural lengths of the original sources, rather than by the artist.

Christian Marclay's extensive body of work revolves around the manipulation and representation of time. Departing from traditional notations associated with duration, Marclay employs more abstract indicators in his performances. By highlighting the materiality and processes in his work, such as breaking and scratching records or repairing them live during playback, he directs the audience's attention to the original sound sources he employs. This serves as a direct acknowledgement of the historical significance of the place and time associated with the original source, which is deemed equally important as the re-appropriated state of sound in the present performance. Perhaps the durational decisions in his work adhere to conceptual rules contingent upon his utilisation of re-appropriated hardware. These objects, constrained by their physical conditions, create instructional and durational sets that Marclay can only maneuver around rather than modify,  manifesting his ability to carve out new spaces within sounds, crafting narratives devoid of a common notation or a conventional understanding of pre-existing (formal) musical rules.

Such artistic endeavors are only conceivable within the carefully constructed environment Marclay has created for them to exist within. Any alterations to the environment would compromise the authenticity of the piece, as the audience requires a contemporaneous and culturally relevant reference to establish a connection between the hardware as the origin of sound and its relation to the present space and time of the performance.

Benjamin's Preservation of Aura in the Age of Technological Reproduction

In Walter Benjamin's renowned essay "The Work of Art in the Age of Mechanical Reproduction" (1948), he explores the notion of aura and its resilience amidst technological reproductions. This critical examination relies on the conditions of authenticity, which have posed significant challenges in the realm of music and sound art. According to Benjamin, the authenticity of an object encompasses its essential qualities that are transmitted from its inception, encompassing its enduring substance and its testament to the historical experiences it has encountered. When substantive duration ceases to hold significance, reproduction jeopardises both the historical testimony and authenticity, leading to the gradual decay or "withering" of the artwork's aura.

‘The authenticity of a thing is the essence of all that is transmissible from its beginning, ranging from its substantive duration to its testimony to the history which it has experienced… That which ‘withers’ in the age of mechanical reproduction is the aura of the art work.’ W, Benjamin (1948)

Benjamin primarily discusses the aesthetic aura of film and photography, which is lost due to the rapid production and fleeting nature of images and visual data ingrained in contemporary society. A single image can be replicated or reproduced an infinite number of times, gradually eroding its original source until it becomes unrecognisable. This cultural and literal distance between an original artwork and its reproductions, despite reaching a larger audience, results in the loss of tradition, cultural understanding, and ultimately the authenticity of the artwork. Utilising or reproducing an image disregards its historical and political significance, further widening the gap between the source and its reproduction. Viewers from different times and spaces would have completely different experiences of the essence or "aura" of the work, despite the visual resemblance.

The question arises: where does the authenticity and ownership of an artwork reside when its creation process relies on technology and its ability to manipulate and intervene with the original material source? Benjamin suggests that ‘through the proliferation of reproductions, the artwork replaces a unique experience with a multitude of copies’. In the case of sound works, particularly those heavily involved in sampling, if the audience lacks the experience of the aura associated with the original sound source and must rely on their imagination to comprehend the origin and technical processing involved in creating a piece, they may be actively seeking a ‘unique’ experience.

Additionally, Benjamin argues that technical reproductions can place the copy of the original in situations that are beyond the reach of the original itself. While the technical processes of reproductions and reappropriations that emerge with new technologies may lack the original aura tied to a specific time and space, they also create their own conditions that can be carefully controlled. Durational artworks, unlike static visual arts, allow for a certain combination of time and space. Nevertheless, it is undeniable that the new experience of the work exists in its unique, irreversible space and time, encapsulating its own fragment of an aura from the past. Perhaps it is this interstitial space between the original and the reproduction that the audience unconsciously seeks.

Certain sound works, such as those by Marclay, appear to transcend some of these concerns. Marclay deliberately embeds the aura of his work by making the creative processes evident, assuming the roles of both musician and conductor in his performances. The hardware he employs does not serve as a replacement for aura, as Benjamin argues reproductions do, but rather acts as a point of reference for the audience. However, when Marclay modifies the hardware, he simultaneously alters the formal or recognisable form through which the audience experiences the work. The deconstructed records he employs physically, references how music is typically consumed by the general public.

Goodman's Analysis of Musical Notation

Nelson Goodman acknowledges that notated musical scores do not possess the auratic presence afforded by Benjamin's work. Goodman distinguishes between autographic and allographic works, utilising his theories of symbol systems and the rules of notation to elucidate the conditions necessary for public comprehension of different art forms and, consequently, their authenticity. The autographic or allographic nature of a work depends on its continued existence after production and the method of its creation. If a work's production does not alter its conceptual basis or the audience's understanding of it, then it is considered allographic. For instance, music is not allographic because each performance of a score is considered the work itself, not a reproduction of it, as long as the performance adheres to the score. ‘In music, the composer's role ends with the completion of the score, even though the performances are the final products’ N, Goodman (1968). The audience witnesses only the performance, not the score, even though the score represents the original work. Whether a performance is based on the original score or a reproduction thereof is inconsequential. ‘The defining properties required for a performance of the symphony are those prescribed in the score’ (1968). A performance may deviate from the score, but the score is where the work and its authenticity resides.

Similarly, music cannot be considered autographic. Autographic works refer to art created directly by the artist's hand, without any reproductions involved before it is presented to the audience. The function of a score differs from that of a sketch or drawing produced by the artist's hand. ‘A score is often regarded as a mere tool, no more intrinsic than a painter's easel, as the score becomes dispensable after the performance and can be learned by 'ear'. Therefore, it is considered nothing more than a practical aid to production’ (1968). However, a work such as a drawing or painting cannot be performed or reproduced by anyone other than its original creator, as it significantly impacts how the work is perceived. The process of production and the symbol systems associated with it are essential to the conception and authenticity of the work in the audience's perception.

Despite the formalities of employing a common notational system, Goodman's theory of symbols indicates that the origin of a sound source and its authenticity remain unaffected by the technological considerations involved in its production, as Benjamin suggests. Music cannot be counterfeited through reproduction. Electroacoustic music does not adhere to a universally standardised notational system, although Erhard Karkoschka has classified symbol systems into four basic types:

1. Precise Notation: Every note is explicitly named.

2. Range Notation: Only the limits of note ranges are specified.

3. Suggestive Notation: Relations between notes or approximate limits of ranges are indicated at most.

4. Musical Graphics.

K, Stone, (1967)

These classifications provide an understanding of the symbol system used in technologically produced sound works up to this point. Having a clearly defined symbol system implies that works are created and assessed within the framework of established conditional structures. In the current common notational system, these systems allow for a wide range of interpretational flexibility when performing a piece live. 

Summary

As an audience, we are adapting to cultural and societal changes, which require us to listen in new ways. We recognise that sounds can convey meaning as signs, signifiers, and symbols. The fundamental structure of our understanding of music has evolved. We understand that perceptions and interpretations of music vary across time and environments. This has led us to investigate the origins of what we hear, particularly in relation to the original sound sources used in electroacoustic music.

Advancements in recording technologies have resulted in the rapid emergence of new forms of instrumentation, surpassing anything seen before. Consequently, there has been a surge in artworks that appropriate old technologies and analog equipment. This convergence of art and science has challenged our perceptions and compelled us to reassess our senses. We are now compelled to examine the intrinsic qualities of sound itself: How was it created? What effects and transformations has it undergone? What modifications have occurred in the sound we hear?

Computer software accessible to the general public has opened up unconventional methods of music production. Layering and the blending of different pitches, tempos, and time scales within a single sound output, potentially emanating from a solitary speaker, have become commonplace in music production.

The environments in which these works take place are of equal importance. According to Goodman, the performance is the final product of a work. Although multiple performances of the same work may vary, they are not reproductions, and two nearly identical experiences may pertain to entirely different works. This perspective contrasts with Benjamin's emphasis on the significance of the "aura." Reproductions of artwork lack the traditional, historical, and cultural values of the original, leading to a loss of aura or essence.

Both Goodman and Benjamin are primarily concerned with the authenticity and ownership of artworks. The authenticity of a sound piece, with an obscured original sound source, is vital for immediate perception and the act of recollecting an experience that solely relied on one sense. Do we, as an audience, hold a sonic idealism regarding the importance of an artwork's original sound source? Are our expectations unattainable? The potential of sound recording is something that should be explored and utilised in the arts. Can an actual piece of nature, such as a recording of the sea or wind directly from the source, be incorporated into an artwork?

The authenticity of using a pre-existing sound will always be in question because its perceptual qualities are more dubious than those of a known man-made sound. For instance, a sound effect designed to mimic a natural sound is clearly an imitation. Therefore, one would expect inconsistencies, mistakes, or inaccurate representations of the original source. Any modification to a recording taken directly from the source raises questions about the artist's intentions and honesty in their portrayal of nature, which is understood as true, beautiful, and genuine.

Bibliography

Smalley, D. (1997). "Spectromorphology: Explaining sound-shapes." Organised Sound, 2(2), 107-126. doi:10.1017/S1355771897009059

Benjamin, Walter. "The Work of Art in the Age of Mechanical Reproduction." In Illuminations, edited by Hannah Arendt, 217-251. New York: Schocken Books, 1968.

Russolo, Luigi. The Art of Noise: Futurist Manifesto, 1913. [New York]: [Something Else Press], 1967.

Emmerson, S. (Ed.). (1994). "Timbre Composition in Electroacoustic Music." Computer Music Journal, 18(2).

Schaeffer, P. (1948). "Études aux chemins de fer."

Christian Marclay. (n.d.). Retrieved from https://www.furious.com/perfect/christianmarclay.html

Goodman, N. (1968). Languages of Art. Indianapolis, IN: Hackett Publishing Company.

Stone, Kurt. (1967). "Perspectives of New Music 5, no. 2." Music Theory Spectrum, 5(2), 146-154. doi:10.2307/832165.