Performing Diffraction:

Reading Michael Baldwin’s Erasure

through Karen Barad’s Agential Realism

I. Position 1


How does Erasure sound?


How does Erasure transform from a set of potential notations, motions, ideas and intentions into the piece that is heard as Erasure? The sound itself, as a physical, actualized event, as well as the relationships between that sound and the litany of agents surrounding it spatially and temporally, is a medium of experience and a laboratory for engaging with the coming-into-being of the musical phenomenon. In Erasure, these webs of interaction are laid bare. Baldwin’s work incorporates into the body of the work all of the fragility of the interconnected physical and mental processes that form the core elements of the production, or realization, of the piece.


How, then, doe Erasure sound? To begin: what does it sound like? The opening gesture: a thin note in the upper register of the trombone that creeps into audibility, slowly and subtly modulated by the performer’s palm on the wawa mute. In the first position of the piece, these minor fluctuations of palm movement constantly modulate the formant content of the slow, microtonal glissandi effected by the performer’s embouchure and slide arm. These subtle changes in overtone content are layered over the constantly shifting microtonal texture of pitches, obscuring and alienating the audible piece from the clear and complex metrical and rhythmic notation that guide the performer’s traversal of this sonic topography. The precise notation metamorphoses into a shimmering mirage of formant and microtonal waves superimposed over each other, flickering in and out of each other’s shadows, alternately reinforcing or obfuscating each other’s gestures in constantly shifting balances of influence.


This interplay of influences, audibly appreciable, is an intrinsically physical effect. The actions notated by Baldwin are physically dissociated, and theoretically removed from each other, yet superimposed and performed within the single body of the performer and their prosthetic instrument, these actions are in constant relation to each other. Static actions become immediately complex situations of constant fluctuation in the context of the holistic physicality of the performer: as noted, a single unaltered pitch constantly undergoes transformation by the superimposition of the wawa mute-cum-filter. In later positions, as further parameters are introduced and more complex actions are prescribed in the score, these elements become ever more apparent. The air stream is constantly modulated by other actions, such as the mute (both wawa and cloth), valve, and slide motions, and the resultant interplay is increasingly foregrounded in the audible musical material as timbral, pitch, and dynamic changes. These qualities of transformation effected by air resistance and other concatenations of physical events are, of course, present in any similar trombone-playing situation, but what distinguishes Erasure is the extent to which these elements, which are conventionally minimized or overlooked, are instead allowed to command aural and theatrical presence as the loci of attention and centers of musical evolution presented in the piece. Indeed, the piece as conceived by Baldwin takes the resultant aural transformations inherent in these physical superimpositions as its primary musical material. The web of dependencies and affects present in the overlaying of these physical gestures is allowed, through their notated dissociation and physicalized reencounter, to constitute the essential aural material of the piece. The extremely soft dynamics and relatively subtle visual gestures of the piece encourage the allocation of prominence to these otherwise easily overlooked (or overlistened) aural textures.


In this sense, then, Erasure sounds through the superimposition of waves of activity, ostensibly quasi-independent though in constant interference with each other. Erasure begins to sound in the moment of intersection of these disparate but inseparable strands of physical material, interwoven into the constantly transforming aural material of the piece. This web of interference, referenced in the title as erasure, can also be constructively conceived through a variety of other theoretical tools. Donna Haraway’s conception of diffraction, in particular, assists a productive reading of Baldwin’s work, and Karen Barad’s own diffractive reading of Haraway alongside her agential realist ethico-onto-epistemology provide profound and useful avenues for a performative analysis of Erasure and its materialization as a sounding phenomenon.


II. Position 2


Barad proposes diffraction as a concept in direct opposition to reflection, and by extension, to an inherited Western tradition of binary oppositions. Scientifically, “Diffraction does not produce ‘the same’ displaced, as reflection and refraction do. Diffraction is a mapping of interference, not of replication, reflection, or reproduction. A diffraction pattern does not map where differences appear,  but rather maps where the effects of differences appear.”1 Theoretically, this also liberates objects or events from being analytically tied to one-to-one relations and simplistic semiotic representations, as is the case in much musical analysis. For example, rather than seeing the relationship of notation to a physical performance as a direct translation, that is, as a one-to-one reflection or representation of a set of denotatively prescribed actions, a diffractive reading allows for the possibility that the two events, notation and performance, are both related and in cooperation and interference with one another, with the performance “mapping” these interferences between the notated and physical aspects of a piece. The traditionally hierarchical relationship between notation and physicalization is problematized by Barad’s proposal of performativity, which uses this concept of diffraction to liberate actions and things from a reflexively consequential reading:


“A performative understanding of discursive practices challenges the representationalist belief in the power of words to represent preexisting things. Performativity, properly construed, is not an invitation to turn everything (including material bodies) into words; on the contrary, performativity is precisely a contestation of the excessive power granted to language to determine what is real. Hence, in ironic contrast to the misconception that would equate performativity with a form of linguistic monism that takes language to be the stuff of reality, performativity is actually a contestation of the unexamined habits of mind that grant language and other forms of representation more power in determining our ontologies than they deserve.”2


Ideally, wresting control from language (or in musical analysis from notation) does not constitute an attack on language or discount it from mattering as a potentially crucial element within a web of diffractive interferences. It does, however, constitute a deprivileging of the linguistic and notational habits that underlie a hierarchical relationship between composer and performer, instrument, listener, or other agents. All of these agents are involved performatively, i.e. actively within the spatio-temporal constraints of a particular version of a piece. This runs the obvious risk of exaggerating some minor agents’ role in the piece, and yet is also a profoundly necessary corrective to more traditional, representationalist hermeneutic methodologies. As Barad emphasizes, “First and foremost, as Haraway suggests, a diffractive methodology is a critical practice for making a difference in the world. It is a commitment to understanding which differences matter, how they matter, and for whom. It is a critical practice of engagement, not a distance-learning practice of reflecting from afar.”3 What is most crucial, then, is the heightened commitment from performatively engaging with a piece. The traditional composer-performer and score-performance dichotomies atrophy responsibility, allowing for a simplistic and reductive representationalist methodology that hinders the recognition of other agents that effect interferences and differences within a piece. Barad’s “commitment to understanding which differences matter” is an invitation to use the theoretical model of diffraction to reveal and examine the complex set of relationships and interdependencies that contribute to the materialization of any phenomenon, musical or otherwise.


Barad’s agential realism applies this diffractive methodology to understand how matter comes into being. It is a scientific account of quantum reality, the exposition of which leads her to coin the term intra-action, which highlights the interdependency of agencies within the localization of phenomena as critical aspects of the coming-into-being of things.


“The notion of intra-action (in contrast to the usual “interaction,” which presumes the prior existence of independent entities/relata) represents a profound conceptual shift. It is through specific agential intra-actions that the boundaries and properties of the “components” of phenomena become determinate and that particular embodied concepts become meaningful. A specific intra-action (involving a specific material configuration of the “apparatus of observation”) enacts an agential cut (in contrast to the Cartesian cut--an inherent distinction--between subject and object) effecting a separation between “subject” and “object.” That is, the agential cut enacts a local resolution within the phenomenon of the inherent ontological indeterminacy. In other words, relata do not preexist relations; rather, relata-within-phenomena emerge through specific intra-actions.”4


The implications for music are clear: entities do not preexist the relations by which a phenomenon (or piece of music, or performance) comes into being, or as Barad phrases it, comes to matter.

III. Position 3


For Barad, the reappraisal of the world in terms of phenomena as opposed to independent objects is a sine qua non feature of agential realism. She posits that “[t]he primary ontological unit is not independent objects with inherent boundaries and properties but rather phenomena...phenomena do not merely mark the epistemological inseparability of observer and observed, or the results of measurements; rather, phenomena are the ontological inseparability/entanglement of intra-acting “agencies.”5 Objects, then, are entangled, and they emerge from their intra-action within phenomena, rather than vice versa. Barad conceptualizes this as “exteriority-within-phenomena,”6 indicating the clear and obvious capability of the participant and observer to distinguish elements and agencies while still acknowledging that they are part of a reality created immanently in and through their intra-action. This immanence is a consequence of a quantum reality described by Barad, first theorized decades ago in the work of Niels Bohr and which is slowly being confirmed experimentally. Transferring the implications of quantum reality to the dimensions of the observable, everyday world is a slippery task, but also a necessary one. As Barad notes, the old conception that Newtonian physics holds for the macrocosmic world and quantum physics for the microcosmic is not confirmed by experimentation and observation; rather, the implications of quantum physics are often miniscule enough in the macrocosmic world that Newtonian physics is merely an aptly accurate-enough model. How, then, do we examine a piece of music in the context of these quantum discoveries?


The sound of Erasure provides an avenue. The sound itself is the phenomenon that conventionally becomes understood as the communicative element of the piece. The sound, emanating from all of the compositional, learning, productive, physical processes, is the physical phenomenon in which these agencies congeal and diffract through one another, intra-acting in the materialization of a recognizable piece of music. Examining the production of sound in the piece, the instrument and the space enlarge their respective realms of diffractive influence. Exaggerating the role of these elements often considered more ancillary or external to the act of musical production is risky, and yet Erasure foregrounds these elements consistently and purposefully. The instrument itself becomes a more active agent in the intra-active phenomenon of the piece largely through the dissociated actions of the mutes and valve, which are, as was previously demonstrated, constantly modulating and metamorphosing the sound waves produced by the performer in the instrument. In a normal piece of music written for the trombone, the instrument is essentially a megaphone, amplifying and reinforcing the pitch produced by the performer’s lips buzzing. This function is, itself, an interesting intra-active process, but also relegates the instrument to a more obviously supporting role‒it is very really a mere mouthpiece for the performer. In Erasure, though, these roles are subtly reversed. The lips produce a buzzed pitch, and Baldwin indicates in the performance notes that “[t]he pitch stave is to be performed “ordinary”, with the mute and trigger actions altering the pitch stave. The pitch stave can be seen as the main pivot stave by which all of the other parameters act upon.”7 Therefore, the buzzed lips are being directly affected and physically changed, not merely amplified. In position 3, the wawa mute has been discarded and the valve is constantly shifting between states of open, closed, and half-valve, with abrupt, gradual, and trilled transitions between valve positions. These valve positions radically alter not only the pitch produced, in spite of the performer’s physical input into the instrument, but also alter the timbre and air resistance, and thus the entire response of the instrument.


The resultant sound waves are dependent on the instrument in many crucial ways. For example, the difference in response and resistance of the half-valve playing varies, sometimes drastically, from instrument to instrument. The aural qualities of this movement will necessarily be different with each different trombone. In conventional classical music performance, these variations from instrument to instrument are traditionally minimized, even when remarked upon or admitted as a factor in the overall performance quality. In Erasure, Baldwin has constructed an environment in which the instrument’s unique characteristics can exert an agency that in some instances rivals that of the performer. In position 3, the performer’s input into the instrument is largely less complex than in the previous positions, and the role of the instrument is then further foregrounded, as the valve action, although enacted by the performer, takes precedence in the resultant sound. The sound waves, although not quite quantum in scale, are nonetheless an essential expression of the phenomenon that is agentially enacted in the performance of the piece. Erasure maximizes the ability for agencies often consigned to ancillary roles to become intra-actively co-responsible and responsive in the production of this sound.

Sketch of potential stand placement for performance,
9 January 2017
(private communication from composer)

IV. Position 4


By opening up agential responsibility to all matter, Barad embraces a form of posthumanism, which for her entails “taking issue with human exceptionalism while being accountable for the role we play in the differential positioning of the human among other creatures (both living and nonliving).”8 Accounting for the deprivileging of the human in assessing the coming-into-being of Erasure requires understanding the types of agency and intra-active responsibility that the nonhuman elements embody. Barad’s description of the material-discursive practices that contribute to the constitution of reality allows us to understand the intricate and powerful role played by the nonhuman without unnecessarily siphoning agency or responsibility from the human actors within the process. Material-discursivity is an extension of concepts of discourse developed by previous philosophers, notably Michel Foucault, a major influence on Barad’s work. Expanding this conception of discourse’s role in shaping and controlling what it is possible to express or perform, Barad notes that matter itself embodies discursive properties. The material-discursive is the posthuman account of how matter shapes and transforms reality constantly and unceasingly. Every moment, every agential cut takes place intra-actively within the material-discursive: “[d]iscursive practices are not human-based activities but specific material (re)configurings of the world through which boundaries, properties, and meanings are differentially enacted. And matter is not a fixed essence; rather, matter is substance in its intra-active becoming‒not a thing but a doing, a congealing of agency.”9


The previous discussion of the instrument already opened up our analysis of Erasure to the post- and nonhuman, but Erasure embraces and problematizes many further facets of the posthuman, as well. Position 4, with the introduction of the cloth mute, marks the agency of increasingly distant and nonhuman elements. Foremost, the cloth mute itself exerts an even greater force of change on aspects of pitch, air resistance, and response than either the wawa mute or the valve alone. The dynamic reshaping of the pitch material in the piece by the constant and occasionally quite drastic modulations effected by the cloth mute come ever more to the fore of the piece, displacing musical and aural attention away from the trombonist and reallocating it to the mute. Further, position 4 also marks the continuation of the gradual removal of the trombonist from the audience: in live performance, the stands are placed in a semicircle, with the trombonist moving from position to position along the curve until the final position facing directly away from the audience. (In the video performance of Erasure presented in this paper, this effect is replaced by the gradual displacement of the audience itself, as both the camera and microphone rove parallel to the trombonist’s displacement in live performance.)

 

This displacement of the performer removes the traditional focal point of attention and reinforces the visual elements of the piece, as at the end of position 4 when the mute is performed solo, without any other parameters active (namely, pitch production). Similarly, the sound, continuously ephemeral and soft, also changes character as the bell of the instrument moves gradually away from the audience. The location itself also takes on a more active role in the piece as the changing acoustics become perceptible or the ambient noise begins to encroach more on the receding imposition of the trombone sound. The role of the mute and especially of the receptive space of the location of performance slowly become more primary containers and agents of musical content and transformation. Erasure opens itself up, displaying a porousness and vulnerability that invites not just the prosthetic elements of the instrument and the mute but all of the agents present in the audience and the location to perforate the musical process and engage intra-actively in the performance of the piece. The material-discursive becomes far more than a mere tacit force exerting control on the productive process, but is actually elicited as an appreciable musical agent of the piece.


V. Position 5


The audience, the location, and the recording devices used (as in the video presented here) all embody part of the observational apparatus, a factor hugely relevant to the world of quantum physics in which agential realism was developed and a major preoccupation of the philosophy-physics of Niels Bohr, another primary influence of Barad’s. The role of the apparatus (experimental, observational, etc.) is difficult to understate in this context: “[a]pparatuses are the material conditions of possibility and impossibility of mattering, they enact what matters and what is excluded from mattering.”10 There can scarcely be greater power than that accorded here to the apparatus, the very agency that enacts or excludes matter, or existence. This, though, distracts from the fact that the apparatus is merely one more element that is cooperative within the diffractive interference of superimposed agencies that intra-act the agential cut. By examining and expanding on Bohr’s own philosophy of the apparatus, Barad arrives at several key features that reveal the apparatus’s unique role in constructing reality:


“(1) apparatuses are specific material-discursive practices (they are not merely laboratory setups that embody human concepts and take measurements); (2) apparatuses produce differences that matter--they are boundary-making practices that are formative of matter and meaning, productive of, and part of, the phenomena produced; (3) apparatuses are material configurations/dynamic reconfigurings of the world; (4) apparatuses are themselves phenomena (constituted and dynamically reconstituted as part of the ongoing intra-activity of the world); (5) apparatuses have no intrinsic boundaries but are open-ended practices; and (6) apparatuses are not located in the world but are material configurations or reconfigurings of the world that re(con)figure spatiality and temporality as well as (the traditional notion of ) dynamics (i.e. they do not exist as static structures, nor do they merely unfold or evolve in space and time).”11


The apparatus produces “differences that matter.” The recording devices, and the observational capacities of the audience, are implicated in the boundary-making practices inherent in apparatuses. Baldwin’s music often inhabits the ephemeral realms between audibility and inaudibility, replicability and unrepeatability, physical and conceptual.12 As Erasure progresses from position to position, these boundaries are increasingly blurred, and can only be enacted by the observational capacities of the audience and recording devices. Their agency becomes critical in the discursive act of creating what is and is not Erasure, in which process they become implicated even more fully in the piece itself. Barad writes, “Apparatuses are not inscription devices...set in place before the action happens..They are neither neutral probes of the natural world nor structures that deterministically impose some particular outcome. In my further elaboration of Bohr’s insights, apparatuses are not mere static arrangements in the world, but rather apparatuses are dynamic (re)configurings of the world, specific agential practices/intra-actions/performances through which specific exclusionary boundaries are enacted. Apparatuses have no inherent “outside” boundary.”13


The observational agents in Erasure are intra-actively involved in the piece. The constant metamorphosis engendered by the superimposition of physical actions leads to the ephemeral shimmering of encounter between performer, location, and observers, forcing the “external” agents to become active within the piece, a part of the agential cut and exterior only within the intra-active process of mattering in the time and space of the performance. Bohr notes precisely the spatial and temporal ramifications of the observer’s activity within the materialization of phenomena. “Temporality and spatiality emerge in this processual historicity. Relations of exteriority, connectivity, and exclusion are reconfigured. The changing topologies of the world entail an ongoing reworking of the notion of dynamics itself.”14

VI. Position 6


The reconfiguring of space and time implicates not only the observational apparatuses of audiences and recording devices, but also reveals crucial aspects of the intra-active entanglement of the performer and composer. The hierarchical model of conventional composer-performer conceptions is temporally deterministic: the work of the composer exists first and, through the medium of the score, determines the role of the performer and dictates the terms of the performance. Bohr’s indeterminacy undermines the very notion of determinism in this sense‒the performance is a result not of temporally hierarchical relationships, but of complementary intra-active processes that encounter and interfere with one another in both temporal directions of the process. Baldwin, quite aware of this, writes that, “[t]he work, and its authorial origin, is gradually evolving and re-contextualizing itself as a result of interacting with a growing number of performative forces, each of which further obscure and dematerialize the work’s ontological identity. Additionally, there is an element of democratization...performers of this work play a significant role in shaping the work’s trajectory and contribute to the performative baggage of each subsequent performance. Through this democratization and the ongoing dematerialization of the score’s ontological identity, the work, in both a physical and aural sense, takes on a lifespan of its own.”15 In Erasure, given the incorporation of the physical dimensions that transform the sound so drastically, the performer is present already in the act of conception and notation. In creating the score for Erasure, Baldwin interacts with the physical demands of the dissociated and superimposed strands of physical material even before they begin to be embodied by the performer. Baldwin recognizes that the “authorial origin” of the work is “evolving,” that the role and work of the composer is altered retrospectively by its intra-action with the work or the performer. His work is superficially a dense, complicated score of polyrhythmic, dissociated physical actions, but within that lies a more complex entanglement with the ephemeral metamorphoses that these superimposed actions enact upon each other and the subtly rich role of external factors in contributing to any realization of the piece. As Barad notes, “knowing, thinking, measuring, theorizing, and observing are material practices of intra-acting within and as part of the world.”16 In examining Erasure we must add to this list composition, notation, and documentation.


The score becomes a crucial medium and agent in the intra-action of composer and performer. In grappling with the precise and challenging rhythmic and coordinational demands of Erasure, the performer must also engage with the composer directly. Just as Baldwin entangles himself with the physical constraints of performance as he composes the situations in which Erasure will emerge, the performer must also entangle herself with Baldwin’s curation of that physicality. In coming to terms with the challenges of the piece, it becomes necessary not only to learn the denotative execution of its precisely-notated actions, but also to embody its vocabulary of physical activity and sonic metamorphosis. There is far more to Erasure than a set of gestures, something Baldwin refers to in later work as a “becoming-document:” “[b]y embracing a process of becoming-document...the human subject is increasingly capable of being composed, and thus manipulated and situated, along lines of musical thinking.”17 The performer and composer are both imbricated directly in each other’s work. The performer must learn to embody Baldwin’s documentation beyond the level of mere execution if the resultant sonic language of the piece is to successfully emerge, and Baldwin must preemptively submerse himself in the performer and the performance if his demarcation of boundaries in the piece’s realization are to emerge. ““[E]mergence,” in an agential realist account, is dependent not merely on the nonlinearity of relations but on their intra-active nature.”18


This, then, is how Erasure comes to sound. The subtle, ephemeral dynamics of the piece that emerge in unpredictable and ever-fluctuating sonic transformations are enacted intra-actively by the composer and performer in complementary aspatial and atemporal discourse, inviting in a host of nonhuman elements in the process. The performer is situated within this web of agencies and is created herself within this agential cut. The work of the performer in preparing and realizing the piece is never solitary or external, but is consistently and very really codependent on other agents in every facet of realization. “Intra-actions effect what’s real and what’s possible, as some things come to matter and others are excluded, as possibilities are opened up and others are foreclosed. And intra-actions effect the rich topology of connective causal relations that are iteratively performed and reconfigured.”19 It is only within and through this entanglement of agencies that the sound of Erasure emerges. The sound is the phenomenon of diffraction enacted and intra-acted performatively and created audibly, perceptibly, consequentially in the world.

VII. Position 7


Embracing this “rich topology” is the first step for a performer in approaching this piece. Recognizing the complex web of intra-actions that enable this piece to come into being means recognizing the responsibility that comes with being a crucial and irreplaceable agent within that process. It means recognizing that these agents all bleed into one another, cooperating and interfering diffractively. Barad reminds us that “edges or boundaries are not determinate either ontologically or visually. When it comes to the “interface” between a coffee mug and a hand, it is not that there are x number of atoms that belong to a hand and y number of atoms that belong to the coffee mug...what one sees is not a sharp boundary between light and dark but rather a series of light and dark bands‒that is, a diffraction pattern.”20 Herein lies Barad’s insistence that the ontological and epistemological ramifications of agential realism are also, necessarily, ethical. She reminds us that “consequentiality, responsibility, and accountability take on entirely new valences. There are no singular causes. And there are no individual agents of change. Responsibility is not ours alone. And yet our responsibility is greater than it would be if it were ours alone. Responsibility entails an ongoing responsiveness to the entanglement of self and other, here and there, now and then.”21 As a performer, Barad considers our obligation to act responsively and response-ably to the agents that surround us as an ethical one. In approaching Erasure, a performer must engage with the whole system in which Erasure emerges, and that means that from the first moments of slowly embodying the complicated rhythmic motions of the piece, the performer must engage responsively with the entire network of composer and situation that are codependent on her. It is impossible to accurately or precisely embody the prescribed actions of the piece without first and foremost approaching and engaging this web of intra-actions.


Baldwin himself recognizes this, writing that “there is a certain degree of responsibility towards the subjectivity of musicking bodies that I consider when treating human persons as scores.”22 He acknowledges that in the process of creation, notation, and even conception, there are already complex implications for the other agents implicated in the work. The performer must meet him there and engage with the piece constructively. The responsibility of embodying the complex physical superimpositions that create the unique and fascinating sonic world of Erasure require that the performer engage principally with those gestures as a holistic system, as a part of a larger web of intra-activity. At that point, the execution of the piece and its precisely layered actions becomes a fluid act, a dynamic entanglement in which the gestures and sounds of the piece emerge and are not merely executed. In this final movement of the piece, position 7, as the trombonist is turned fully away from the audience and playing with a practice mute, this fluidity is most concretely embodied in the piece. Layered over the fluttering valve motions, in a metrical grid that has underlaid the piece from its very first measures, the trombonist alternates singing and playing as seamlessly as possible. The varieties of sound production diffract through the valve, mute, and situation, melding one into the other and erasing distinctions. The erasure of aural identity and subsumption of superimposed techniques in this passage embodies Erasure’s total entanglement of creative processes: compositional, performative, bodily, mental, theoretical, situated. In Erasure, the intra-active demands and responsibilities do not appear retrospectively in performance but are implicated in the very first as well as final moments of creation and coming-into-being. Performing Erasure means performing the entire material-discursive network within which it materializes in the world. Whether this awareness is interpreted metaphorically or, as is posited here, as a fundamental part of the reality of the piece is ultimately unimportant. What matters is that the embodiment of the piece emerges from the performer’s entanglement with the piece rather than from an attempt to be an exterior or independent actor. Barad writes, “There is no such exterior position where the contemplation of this possibility makes any sense. We are of the universe‒there is no inside, no outside. There is only intra-acting from within and as part of the world in its becoming.”23

ENDNOTES


1 Donna Haraway in Karen Barad, “Posthumanist performativity: towards an understanding of how matter comes to matter,” Signs: Journal of Women in Culture and Society 28, no. 3 (2003): 803 (Donna Haraway, “The Promises of Monsters: A Regenerative Politics for Inappropriate/d Others,” in Cultural Studies, ed. Lawrence Grossberg, Cory Nelson, and Paula Treichler  (New York: Routledge, 1992), 300).

2 Barad, Posthumanist performativity, 802.

3 Karen Barad, Meeting the universe halfway: quantum physics and the entanglement of matter and meaning (London: Duke University Press, 2007), 90.

4 Barad, Posthumanist performativity, 815.

5 Barad, Meeting the universe halfway, 139.

6 Barad, Posthumanist performativity, 815.

7 Michael Baldwin, Erasure (Bowling Green, Ohio, USA: self-published, 2011), https://michaelbaldwincomposer.files.wordpress.com/2011/08/erasurenotes.pdf, accessed 11 October 2016.

8 Barad, Meeting the universe halfway, 136.

9 Ibid., 183-4.

10 Ibid., 148.

11 Ibid., 146.

12 see Michael Baldwin, Reflections on ephemerality and notation in my recent work (2012), https://michaelbaldwincomposer.files.wordpress.com/2013/01/repository_thesis_baldwin.pdf, accessed 12 December 2016.

13 Barad, Posthumanist performativity, 816.

14 Barad, Meeting the universe halfway, 141.

15 Baldwin, Reflections, 39-40.

16 Barad, Meeting the universe halfway, 90.

17 Michael Baldwin, Effaced reflected being: musicking bodies and/of/as documentation, personal communication, 8 October 2016, 120-1.

18 Barad, Meeting the universe halfway, 393.

19 Ibid.

20 Ibid., 156.

21 Ibid., 394.

22 Baldwin, Effaced reflected being, 120-1.

23 Barad, Meeting the universe halfway, 396.