Written in 1996-7 in close collaboration with percussionist, composer, and improviser Brett Reed, Altered in Transmission traces a path between composition and improvisation. At the beginning, the performer interprets a traditional score; by the middle, performer and computer improvise together using gestures written as excerpts from a set of six poems.
The music explores behavior more than sound. Cort Lippe has even described it as "anti computer music," since all the sounds are very close to the vibraphone itself. The computer provides a virtual vibraphonist with a subtle and multi-dimensional model of the "rules" for improvising in this piece. Simple effects processing is applied to both real and virtual vibraphonists: a multi-tap delays refract notes and passages; an enveloped sample player "rings" notes; a flanger extends the sound of the vibraphone motor; a distortion algorithm extends the sound of keys buzzing as they fall to the keybed; a carefully tuned frequency shifter adds a ghostly dimension to the vibraphone's timbre and harmony; and simple four-channel distribution of sound creates an uneasy conversation between the front and back of the hall.
The computer's software uses Cycling74's Max environment, and should run under either Mac OS or Windows on any modern machine with a 4-channel audio card. It was originally written in IRCAM's Max/FTS, but this version is no longer maintained. A second performer runs the computer, following the written score.