The author discusses the conceptual basis of an ecological approach to music composition, considering the epistemological and compositional concepts involved. The author's text-and-tape piece, touch'n'go/toco y me voy, is presented as an example of an ecologically based musical work, in which the sound event functions as the basic unit of multilevel musical structures. Digital resynthesis techniques are integrated in the compositional process by means of environmental sound models. Ecological models establish formal relationships without obscuring the recognizability of everyday sounds. Materials, techniques, perceptual constraints and references to social issues are integrated in a consistent compositional method.