Les sphères englobantes
Les sphères englobantes is a piece of music whose notation is generated in real time by a software algorithm to be performed live by musicians. It was composed and programmed by Drake Andersen in 2015. It was commissioned by contemporary music ensemble NOISE-BRIDGE specifically for a concert on the Musik der Jahrhunderte series in Stuttgart, Germany in 2015.
The premiere performance took place on May 8, 2015. In this performance, three ensembles interspersed movements of compositions from diverse repertory in a continuous flow of music. Les sphères englobantes was composed with this setting in mind. The pitches and note lengths are selected via algorithm, but many other interpretive elements, including duration, pulse and dynamics, are left more or less to the discretion of the performers.
The organizing principle of this piece is very similar to Indra, but the process of creating the work is very different. Pieces using Indra comprise complete images of notation stored in a database, whereas the notational interface for this piece is much simpler, comprising only pitches and note lengths in a relatively stable pattern. Owing to the relative simplicity of the interface, the performers have broader interpretive latitude in this piece, and the music can be arranged in any texture or combination.
The title of the piece translates to “the bounding spheres”. This concept is embodied by the sound world of the piece, which gradually expands as the algorithm generates new notation for the performers to play. Each new gesture and interpretive choice by the performers creates new data points and expands the sphere. In listening to multiple iterations of the piece, certain patterns emerge, but each performance is undeniably quite different. In addition, the balance between what is constant and what is malleable between performances suggests the possibility of multiple spheres.
The following program note is provided by the composer:
The material of this composition is a software program that generates music notation by algorithm in real time for the musicians to perform. As new notes are generated and the performers make interpretive choices, the sound world of the piece increases exponentially. The title refers to the mathematical concept of the smallest possible sphere which encompasses a given set of three-dimensional data points: the bounding sphere.
Premiere Performance: First Movement
Premiere Performance: Second Movement
Premiere Performance: Third Movement
These recordings were made in the days before the premiere performance. By comparing them with the final performance, you can hear what changes with each performance.