Song Walker : Embodied Interaction Design for Harmony

Tonal Harmony is widely considered to be the most technical and complex part of music theory, and harmonic skills can be hard to acquire. Experience of the precise and flexible manipulation of harmony in real time generally requires hard-won instrumental skill. Even with instrumental skills, it can be hard to gain clear insight into harmonic abstractions. The above state of affairs gives rise to substantial barriers not only for beginners but also for many musicians. To address these problems, Harmony Space [Holland et al, 2009] is an interactive digital music system designed to give insight into a wide range of musical tasks in tonal harmony ranging from performance and composition to analysis. Harmony Space employs a principled set of spatial mappings to offer fluid, precise, intuitive control of harmony. These mappings give rise to sensory-motor, music-theoretic and information-theoretic affordances that are not readily obtainable in any other way. The result is that a wide range of harmonic abstractions are rendered amenable to concrete, visible manipulation by simple spatial means. In the language of conceptual metaphor theory, most relationships in tonal harmony become accessible, to rapid, universal, low-level, robust human inference mechanisms using image schema, such as containment, contact, centreperiphery, and source-path-goal, in place of slow, abstract symbolic reasoning. While keeping the above principles invariant, different versions of Harmony Space have been designed to exploit different detailed interaction styles for different purposes. We note some key variants, such as the desktop version [Holland, 1994], the camera tracked version [Holland et al., 2009], and the most recent whole body version, Song Walker [Holland et al., 2011]. Preliminary results from a recent study of the Song Walker system are outlined, in which both beginners and expert musicians undertook a range of solo and collaborative musical tasks involving the performance, composition and analysis of music. Finally, we offer a discussion of the limitations of the current system, and outline directions for future work.