Over the past half century, there has been much research into the acoustic qualities of soundscapes from a variety of perspectives: the humanities and social sciences as per the ‘acoustic ecology’ movement (established by Schafer, Truax, and Westerkamp et al.), and more recently the environmental science and ecology as per ‘soundscape ecology’ (established by Farina, Pijanowski, and Krause, et al.). Collectively, these disciplines provide diverse methods for engagement with analysis of acoustic environments. Simultaneous to the rise of the acoustic ecology movement in the 1970s (marked by the publication of Schafer’s ‘The Tuning of the World (1974)), the composition of numerous seminal ‘minimalist’ musical works occurred, notable amongst them Steve Reich’s ‘Music For 18 Musicians’ (1974-6). Whilst there has been significant analysis of this work from a traditional musicological standpoint, the environmental implications of its process-driven nature have gone largely ignored, particularly in relation to ecological processes and behaviours. This paper provides an ecomusicological analysis of ‘Music for 18 Musicians’, investigating the numerous affinities that the piece has with acoustic ecology and soundscape ecology concepts alike. This will be explored at both a macromorphological level (considering large-scale temporal cycles and processes), and micromorphological level (as related to orchestration, textural organisation, instrumental content in the context of bioacoustics, community sound cues and ensemble agency). A concluding discussion of Reich’s compositional influences (themselves influenced by natural soundscapes) and process follows, with questions raised around the possibility of ecomusicological analysis of other ‘abstract’ musical works to encourage further research in compositional approaches and music therapy.