Expression and Spatial Motion: Playable Ambisonics Joanne Cannon Bent Leather Band Christmas Hills VIC, Australia +613 9730 1026 joanne_cannon@bigpond.com Stuart Favilla Bent Leather Band Christmas Hills VIC, Australia +613 9730 1026 sfavilla@bigpond.com ABSTRACT This paper presents research undertaken by the Bent Leather Band investigating the application of live Ambisonics to large digital-instrument ensemble improvisation. Their playable approach to live ambisonic projection is inspired by the work of Trevor Wishart and presents a systematic investigation of the potential for live spatial motion improvisation. Keywords Playable instruments, augmented instruments, expressive spatial motion, ambisonics 1. BACKGROUND Bent Leather Band began experimenting with spatial sound during the early 1990s. It seemed a logical step as electronic musicians, to do something with sound using a loudspeaker field. The potential to move sounds in space, affect multi- channel echoes and delays and generally do things beyond the realms of conventional acoustic instruments, was exciting to say the least. The spatial projection works of Varese, Xenakis and Stockhausen were of great inspiration to us in our student days. As instrumentalists and improvising musicians, we dreamt of spatial motion, diffusion and effects as intrinsic expressive parameters in our live ensemble music. Back then, computer technology for spatial projection was simply not available to musicians like us, we were left to construct our own rudimentary joystick audio mixers [see fig. 1]. These devices were designed to mix a mono input across four separate outputs and were set into large plastic jiffy boxes with a joystick on top and jack connectors on the sides. Those simple CMOS circuit boards although a mess of wires, crystal clocks and op-amps, enabled us to pan and move our sound with some success. Reverbs, delays and filtering were added in an attempt to simulate distance cues and to add dimension to our mix. We began by presenting spatial sound concerts and gigs. After the initial novelty wore off, we stumbled into a morass of technical challenges. First of all, pans were best heard from the central area also known as the “sweet-spot”. This area was rather small and could only encapsulate either the musicians or about 5-10 seats for the audience. Also sounds would always perceptually be located at the periphery of the field and although our joystick mixers could easily pan diagonally across, the perceived course of the sound clearly did not travel in this fashion. There were also technical challenges setting up a four channel PA system in conventional concert environments. Acoustic reverb was critical to the spatial ensemble definition often washing out the detail and presence of audio. Acoustically dead cinemas were the favourite venues. Fig 1. Joystick Audio Mixers, 1990’s style There were significant musical issues too. We discovered through our manual control that spatial motion is complex to perform being both control and performance feedback intensive. Performing a beautiful series of spins and rapid trajectories required a large cognitive load leaving little thought to do much else musically. Conventional musical language and form has little or no correlation to spatial motion. We tried Ambient pieces but these held only limited fascination, usually resulting in the audience tilting their heads backwards and going to sleep. The best success we had involved playing a rainforest of abstract bird and insect languages and mixing it up live. Here the audience and musicians had a clear understanding and appreciation of the piece, i.e. an immersive experience where synthesized sound’s dynamics were mixed spatially. At that stage, our research interests shifted towards developing new expressive controllers, virtuosic techniques and ensemble music language. Spatial sound was abandoned because of its capacity to decentralize the live musician and constrict control Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. NIME2010, June, 15-18, 2010, Sydney, Australia Copyright remains with the author(s). Proceedings of the 2010 Conference on New Interfaces for Musical Expression (NIME 2010), Sydney, Australia 120