Heinrich Taube

Composing in Common Music and Stella

Abstract

Common Music is an object oriented software environment designed to support both algorithmic and non-algorithmic styles of music composition. It may be used in conjunction with a variety of different synthesis languages as well as notation programs such as

CMN

William Schottstaedt, CMN Computing in Musicology 8, 1992

(Schottstaedt 1992), Finale, or Score. Common Music is hardware independent and runs on most standard workstations and PCs. It provides flexible, open ended class definitions for the representation of musical structure, ranging from individual parameter and note definitions to large scale compositional organizations such as gestures, phrases, algorithms, and sections. Common Music also provides a large numbers of classes and operators for defining and working with compositional abstractions like interval sets, scales, rhythms, and amplitudes. A composition editor called Stella facilitates the creation and modification of musical structure and data. In addition to editing and processing commands, Stella implements a powerful object referencing scheme and a query language for the algorithmic examination of parameterized sound event data. A graphic interface for Stella is currently being implemented for the Macintosh.

Introduction

The past decade has witnessed a marked increase in the general availability of sound synthesis programs that run on standard workstations and PCs. Though the availability of these programs is a tremendous asset for the contemporary composer, it also raises some difficult compositional issues. Though often sharing common concepts, every synthesis language has a unique set of strengths and weaknesses. Since these languages deal with specific sound descriptions, their level or abstraction is too low to represent most of the structural and pattern issues that composers are normally concerned with. Common Music grew out of the author's desire to define a flexible, open ended composition environment in which high level compositional issues may be addressed and which may be used in conjunction with all the commonly available syntheses languages. One of the central aims of Common Music is to make composing for synthesis languages as transparent as possible without changing the manner in which compositions are described. Synthesis is controlled in Common Music by selecting an output syntax. A single composition may be used in conjunction with several synthesis languages by selecting different output syntaxes. Common Music has been designed to support the incremental addition of new syntaxes without changing the code or behavior of the preexisting system.

Another central aim of Common Music is to be portable and hardware independent. This allows the system to take advantages of hardware platforms as needed