Book excerpt: Ubiquitous music is an interdisciplinary area of research that lies at the intersection of music and computer science. Initially evolving from the related concept of ubiquitous computing, today ubiquitous music offers a paradigm for understanding how the everyday presence of computers has led to highly diverse music practices. As we move from desktop computers to mobile and internet-based multi-platform systems, new ways to participate in creative musical activities have radically changed the cultural and social landscape of music composition and performance. This volume explores how these new systems interact and how they may transform our musical experiences. Emerging out of the work of the Ubiquitous Music Group, an international research network established in 2007, this volume provides a snapshot of the ecologically grounded perspectives on ubiquitous music that share the concept of ecosystem as a central theme. Covering theory, software and hardware design, and applications in educational and artistic settings, each chapter features in-depth descriptions of exploratory and cutting-edge creative practices that expand our understanding of music making by means of digital and analogue technologies.