ECHO::Canyon (2013) by Rob Hamilton and Chris Platz is an interactive musical performance piece built within UDKOSC, a modified version of the Unreal Development Kit or UDK, a free-to-use version of the commercial Unreal 3 gaming engine. Premiered on April 25, 2013 at Stanford University's Center for Computer Research in Music and Acoustics, ECHO::Canyon creates a reactive musical environment within which the idiomatic gestures and motions of flight are mapped to musical sound-producing processes.

Performers control virtual actors flying through a fully-rendered outdoor landscape using a computer keyboard and mouse or commercial game-pad controller. Each actor's location and rotation in game-space, as well as other parameters describing their interactions with objects within the environment are streamed in real-time to sound-servers using the Open Sound Control (OSC) protocol. Individual bones that comprise each avatar skeleton are also tracked over OSC, turning every twist and turn, wing flap and arm reach into musical controllers. The environment itself is sculpted in such a way as to allow performers the freedom to perform musical interactions by moving above, around and through the topography. In this way the process of environment design takes on the role of composition, with sections of virtual hills, canyons and valleys acting as musical pathways through the environment.

While ECHO::Canyon is built within a gaming engine, unlike many commercial games where audio and music play a supporting role to displays of rich visual content, the role of music and sound within the work are intended to occupy a perceptual role equal to the presented visual modality. Sonifications used in ECHO::Canyon are designed to be musical and performative in nature, and are fundamentally presented as foreground constructs, rather than as background or more associative “sound-effect” constructs. To that end traditional approaches for game sound design are replaced instead by sets of composed interactions.

Audio for ECHO::Canyon is generated in Supercollider using ambisonic spatialization, allowing interactions happening throughout the environment to be positioned around a listening space.