The SINE WAVE ORCHESTRA (SWO) is a collaborative sound performance project that has been actively performing for the past several years. The basic idea is that each participant plays a sine wave, and by changing its frequency and volume, creates a collection of sine waves as a collective sound representation. Although all SWO works use the same sound representation (i.e., sine waves), different SWO works use different temporal, physical, environmental, and procedural settings. The different settings have resulted in different types of sound experiences for the participants. This paper examines six of the SWO works and discusses what aspects of the settings affect how people engage in collective sound representations. T he network prevalence and the advance of communication technologies work as enablers for a variety of collective representation projects to emerge (Jorda 2005)(Weinberg 2002). Collective sound representations have varied forms, which can be

In this paper the authors present an overview of recent work on ongoing projects at the Audiovisual Institute from the Pompeu Fabra University in Barcelona, focused on Internet collaborative virtual environments for music applications. Although presenting different strategies, they all put a special emphasis in performance and composition/production of music by groups of geographically dispersed communities of users, both in synchronous and asynchronous modes.

We outline work on web based support for group creativity. We focus on a study of the e#ect persistence of participants' musical contributions has on their mutual engagement.