Orchestra!: a distributed platform for virtual musical groups and music distance learning over the Internet in Java/sup TM/ technology

This paper proposes a platform for musical group sessions over the Internet. It has been conceived as an useful instrument for collaborative music developing and enjoying, both at the professional and at the "amateur" level. It has been designed for music distance learning, as well. The system, that we named "Orchestra!", is based on a distributed software architecture and its services are universally accessible through a simple http-client (a browser) and a sound card. Geographical packet-switched network latencies make it impossible to reach a real musical synchronisation among all members of a virtual group. As an alternative, it has been developed a system of progressive and collaborative elaboration of musical audio streams which is insensitive to delays: this idea permits to reproduce "live" performances as well as recording studio activities.