Courtney N. Reed

This article examines how digital systems designers distil the messiness and ambiguity of the world into concrete data that can be processed by computing systems. Using Karen Barad’s agential realism as a guide, we explore how data is fundamentally entangled with the tools and theories of its measurement. We examine data-enabled artefacts acting as Baradian apparatuses: they do not exist independently of the phenomenon they seek to measure but rather collect and co-produce observations from within their entangled state: the phenomenon and the apparatus co-constitute one another. Connecting Barad’s quantum view of indeterminacy to the prevailing HCI discourse on the opportunities and challenges of ambiguity, we suggest that the very act of trying to stabilise a conceptual interpretation of data within an artefact has the paradoxical effect of amplifying and shifting ambiguity in interaction. We illustrate these ideas through three case studies from our own practices of designing digital musical instruments (DMIs). DMIs necessarily encode symbolic and music-theoretical knowledge as part of their internal operation, even as conceptual knowledge is not their intended outcome. In each case, we explore the nature of the apparatus, what phenomena it co-produces, and where the ambiguity lies to suggest approaches for design using these abstract theoretical frameworks.

Research at NIME has incorporated embodied perspectives from design and HCI communities to explore how instruments and performers shape each other in interaction. Material perspectives also reveal other more-than-human factors’ influence on musical interaction. We propose an additional, currently unaddressed perspective in instrument design: the influence of the body not only the locus of experience, but as a physical, entangled aspect in the more-thanhuman musicking. Proposing a practice of “Body Lutherie”, we explore how digital instrument designers can honour and work with living, dynamic bodies. Our design of a breathbased vocal wearable instrument incorporated uncontrollable aspects of a vocalist’s body and its physical change over different timescales. We distinguish the body in the design process and acknowledge its agency in vocal instrument design. Reflection on our co-design process between vocal pedagogy and eTextile fashion perspectives demonstrates how Body Lutherie can generate empathy and understanding of the body as a collaborator in future instrument design and artistic practice.

This paper investigates sound and music interactions arising from the use of electromyography (EMG) to instrumentalise signals from muscle exertion of the human body. We situate EMG within a family of embodied interaction modalities, where it occupies a middle ground, considered as a “signal from the inside” compared with external observations of the body (e.g., motion capture), but also seen as more volitional than neurological states recorded by brain electroencephalogram (EEG). To understand the messiness of gestural interaction afforded by EMG, we revisit the phenomenological turn in HCI, reading Paul Dourish’s work on the transparency of “ready-to-hand” technologies against the grain of recent posthumanist theories, which offer a performative interpretation of musical entanglements between bodies, signals, and representations. We take music performance as a use case, reporting on the opportunities and constraints posed by EMG in workshop-based studies of vocal, instrumental, and electronic practices. We observe that across our diverse range of musical subjects, they consistently challenged notions of EMG as a transparent tool that directly registered the state of the body, reporting instead that it took on “present-at-hand” qualities, defamiliarising the performer’s own sense of themselves and reconfiguring their embodied practice.