Revision with unchanged content. This Book derives from research on musical practices mediated by computer networks conducted from 2001 to 2005 in the Music Technology Group of the Pompeu Fabra University in Barcelona, Spain. It departs from work carried out over the last decades in the field of Computer-Supported Cooperative Work, which provides us with collaborative communication mechanisms that can be regarded from a music perspective in diverse scenarios: Composition, Performance, Improvisation, Interpretation or Education. The Book presents an extensive survey and systematic classification of Computer-Supported Cooperative Work for Music Applications. This survey led to the identification of innovative approaches, models and applications, with special emphasis on the shared nature of geographically displaced communication over the Internet. The notion of a Shared Sonic Environments was introduced and implemented in a proof-of-concept application entitled Public Sound Objects (PSOs). This work also introduces innovative methods reduce the disrupting effect of network latency in musical communication over long distance networks.