A generative machine for a piece
In Topology (phases of this difference), my goal was to create a compositional system that generated pieces deterministically, based on the latitude and longitude of a given performance venue. However, there are a number of qualities that all versions of the piece share. They each consist of 29 nine-note melodies played in hocket by two violins. The intervals between pitches are tuned in just intonation, ranging from 8/7 (a wide major second) to 8/1 (three octaves), drawn from a set of intervals tuneable by ear outlined in Sabat (2004). Only the central melody (#15) stays the same from performance to performance, while all others shift depending on the latitude and longitude of the venue. Using the morphological metrics described in Polansky (1996), the 28 changing melodies are found by transforming the central melody until it is a certain “distance” away from its starting point. The first 14 melodies gradually move closer to the central melody, while the last 14 move further away. Thus, the piece is coherent from performance to performance—as in, the same basic actions take place, using the same instruments, and the piece is roughly the same length with the same figure in the middle—and yet the content of the composition changes with each new location.
Fundamental to this project is the creation of a piece that contains a range of possible performances, rather than a fixed work unto itself. This way, the final note-to-note decisions are not left up to the composer (or even to the performer) but are meant to reveal an aspect of the generative machine behind the work. With each new performance location, a new expression of this machine is articulated.
Recorded by Conrad Harris and Pauline Kim Harris at Benzaquen Hall, DiMenna Center for Classical Music, engineered by Alexis Berthelot and mastered by Joseph Branciforte. Released on Index 0, by Indexical.