Computer Music Journal, 26:4, pp. 69–82, Winter 2002 2002 Massachusetts Institute of Technology. Eric Lyon organized this symposium around the following two questions. Why has some computer music software survived and developed a following? Where is computer music software today, and where might it be headed in the future? Acknowledging that the term ‘‘computer music’’ is by now redundant, since virtually all music involves the use of computers in some form or another, he posed these questions with respect to computer music software that supports experimental music. Experimental music is not limited to any specific musical style or genre. An experimental musician is one who approaches each act of musical creation in a spirit of exploration and innovation, often with the goal of inventing new kinds of music that have never been heard before. I would like to take Eric Lyon’s refinement a step further by observing that all of the software examples included in this symposium (along with some others that are not represented here) belong to a special category of computer music software called computer music languages. Most software packages can be classified as utilities; they perform a welldefined, familiar function that is needed by a large number of people. A software package that emulates all the functions of the traditional multi-track recording studio would be one example of a utility. But the pieces of software that Eric Lyon has chosen to include in this symposium are different; they are examples of computer music languages. A language provides one with a finite set of ‘‘words’’ and a ‘‘grammar’’ for combining these words into phrases, sentences, and paragraphs to express an infinite variety of ideas. A language does not do anything on its own; one uses a language to express one’s own thoughts and ideas. This is what makes these particular software packages so open, extensible, and useable in ways unanticipated by their authors. And that is why, although they may never command the same market share as utilities, they have had a longer-lasting and deeper influence on the evolution of music. This article is organized into three sections. The first section is an identification and discussion of factors that can contribute to the success and longevity of a computer music language. In the middle section, I try to illustrate some of those factors (like extensibility) using specific examples from the Kyma language. The last section is a speculation on the role computer music languages could play in a future world where art, the economy, and human beings are very different from the way they are today.