We describe the prevailing model of musical expression, which assumes a binary formulation of "the text" and "the act", along with its implied roles of composer and performer. We argue that this model not only excludes some contemporary aesthetic values but also limits the communicative ability of new music interfaces. As an alternative, an ecology of musical creation accounts for both a diversity of aesthetic goals and the complex interrelation of human and non-human agents. An ecological perspective on several approaches to musical creation with interactive technologies reveals an expanded, more inclusive view of artistic interaction that facilitates novel, compelling ways to use technology for music. This paper is fundamentally a call to consider the role of aesthetic values in the analysis of artistic processes and technologies.