Biomimetic Agent-Based Modeling in Musical Interface Design: Ecological Dynamics, Care, and Constraint in a Physarum-Inspired Musical Instrument

What happens when a digital musical instrument can die? This thesis argues that ecological dynamics can function as musical interfaces whose behavioral logic shapes timbre, event structure, and the performer-instrument relationship. While much of the existing discourse in computer music addresses models' role in sound generation, an equally important question concerns their role in structuring performer interaction. The thesis argues that Döbereiner's framework distinguishing standard from nonstandard synthesis can be extended to interface design: just as nonstandard synthesis foregrounds the model's operations at the sample level, the gestural level foregrounds the model's operations between performer and sound. At this level, behavioral dynamics shape timbre and event structure not by generating sound directly but by structuring how the performer interacts with the system. The thesis develops a theoretical framework drawing on predictive processing (Rao and Ballard 1999; Clark 2013), Puig de la Bellacasa's ethics of care (affective, material, and political dimensions), and situated cognition to derive four testable design principles: three-dimensional care, legible non-determinism, visible biological behavior (anthropomorphization), and temporal depth. Legible non-determinism names the criterion at the center of this framework: variability arising from the system's own evolving response rather than from injected randomness, producing behavior that can be read even when it cannot be predicted. Two instruments test these principles through a research-through-design methodology. Spores (2025) is a Physarum-inspired touchscreen instrument in which a simulated slime mold colony becomes the control surface for timbral modulation and compositional structure. Rather than commanding the system, the performer tends it, distributing resources and creating disturbances while the organism's survival logic shapes synthesis parameters. Sound emerges as a byproduct of care: no food, no colonies, no sound. Mini Spore extends the framework to an ESP32 microcontroller, shifting from environmental tending to single-colony care and introducing genetic degradation, a mechanism that permanently diminishes the device each time a colony dies. Where Spores engages primarily the affective and material dimensions of care, Mini Spore tests the political dimension: whether permanent consequence makes care structurally real rather than rhetorically invoked. Expertise with such systems is interpretive rather than procedural. The performer learns to read organism state, not to master input-output mappings, and anthropomorphization of the system's behavior functions as the mechanism of that expertise rather than as perceptual error. The evidence is autoethnographic and limited to one performer who is also the designer. The thesis documents what ecological interfaces require, demonstrates that they are feasible across platforms, and identifies where the framework remains speculative.

Name thesis:degree_name

Music Technology, MS

Grantor

Georgia Institute of Technology

Year dc:date.issued

2026

Author dc:creator

• Smith, Kyle Braden

Advisor dc:contributor.advisor

• Smith, Alexandria

Committee members dc:contributor.committeemember

• Arthur, Claire
• Danahy, Patrick

Language dc:language.iso

English

Handle dc:identifier.uri

https://hdl.handle.net/1853/81628

OAI identifier oai:identifier

oai:repository.gatech.edu:1853/81628