light.void~: An Autographic Case Study on Approaches, Constraints, and Affordances with a Light-dependent Musical Interface.

This paper discusses the strategies, considerations, and implications of designing and performing with a light-dependent digital musical interface (DMI), named light.void~. This interface is introduced as a replica of light thing, an existing DMI designed and popularized by British artist Leafcutter John. The rationale for reproducing this DMI is presented, followed by a discussion around the guiding criteria for establishing data-to-sound mappings, and the kind of affordances that these decisions may bring — including performer control, unpredictability, intentionality, spontaneity, action-sound reactivity, visual interest, and so on. The remainder of the paper focuses on dissecting the nature of this digital musical instrument, using contributions by DMI researchers Miranda and Wanderley as the main analytical framework. The outcome of this process is a semi-improvisational work titled «Umbra», along with the open source documentation for the light.void~ interface. Additionally, some relevant questions emerge with regards to performer expertise, observed vs. unobserved performance, as well as ontological frictions between instrument, composer, performer, designer, and audience.