The ubiquitous nature of communication in computer networks, firmly manifested in the Internet era, provided a context for the introduction of different collaborative tools widely accepted by the on-line community, such as textual chats, white boards, shared editors, video conference systems, shared spaces for the exchange of multimedia documents or even simple e-mail based collaborative systems.

A Network Musical Performance (NMP) occurs when a group

The standard “ping ” utility provides a momentary measurement of round trip time. Sequences of ping events are used to gather longer-term statistics about jitter and packet loss in order to describe the quality of service of a network path. A more finegrained tool is needed to evaluate paths which carry interactive media streams for collaborative environments. Natural interaction depends on obtaining consistent low-latency, low-jitter service, something which normally requires several ping “takes ” to assess and even then only provides an averaged picture of quality of service. We have designed a stream-based method which directly displays the critical qualities to the ear by continuously driving a bidirectional connection to create sound waves. The network path itself becomes the acoustic medium which our probe sets into vibration. The granularity of this display better matches the time-scales of variance that are important in interactive applications (for example, bidirectional audio streams for long-distance musical collaboration or high-quality teleconference applications). The ear’s acuity for pitch fluctuation and timbral constancy make this an unforgiving test. A related sonification technique is discussed which is a sonarlike mapping of momentary ping data to musical tones. Temporal levels of musical foreground, middleground and background can be heard in the melodies derived from the data and correspond to structures that are of importance in the analysis of network performance. 1.

Since telecommunication can never equal the richness of face-to-face interaction on its own terms, the most interesting examples of networked music go beyond the paradigm of musicians playing together in a virtual room. The Open Sound Control protocol has facilitated dozens of such innovative networked music projects. First the protocol itself is described, followed by some theoretical limits on communication latency and what they mean for music making. Then a representative list of some of the projects that take advantage of the protocol is presented, describing each project in terms of the paradigm of musical interaction that it provides. 1.

Distributed physical models of musical instruments have been used to acoustically “ping ” Internet connections between two network hosts. Sound waves propagated through Internet acoustics behave just as in air, water or along a stretched string. In this case, a musical synthesis technique creates waves on the Internet path between two hosts. When waves recirculate between two endpoints, a musical tone is created if the round trip travel time lies within the range of our pitch sense (roughly  ¢¡¤£¤¥§¦ to ¡¤£©¨� ¦). The result-ing tones provide a quick and intuitive evaluation of quality of service (QoS), displaying its significant aspects including latency, jitter and packet loss. Stable, clear tones with high pitch indicate good end-to-end capabilities that a path must support for immersive, real-time applications. A “network harp ” recently demonstrated 320 synthesized strings oscillating across the Western half of the Internet2 Abilene Network. 1.

This paper questions and examines the validity and future of interactive network performance. The history of research in the area is described as well as experiments with our own system. Our custom-built networked framework, known as GIGAPOPR, transfers high-quality audio, video and MIDI data over a network connection to enable live musical performances to occur in two or more distinct locations. One of our first sensor-augmented Indian instruments, The Electronic Dholak (EDholak) is a multi-player networked percussion controller that is modelled after the traditional Indian Dholak. The EDholaks trigger sound, including samples and physical models, and visualisation, using our custom-built networked visualisation software, known as veldt. 1.

The conditions of networked ensemble performance were simulated in an experiment. Pairs of musicians were placed apart in isolated rooms and given a simple rhythm to clap together. A microphone was placed as close as possible to each performer’s hands. Each monitored the other’s sound via headphones, and a delay was introduced between the source and listener. Starting tempo, given by a recorded count-in, and delay time were varied across trials. Recordings of the trials were analyzed with a precise event detection algorithm to locate clap onsets, from which the tempo was inferred. The rate of deceleration increased with longer delays, while shorter delays ( 11.5 ms) produced a modest, but significant acceleration. The goal is to identify the region of delay time that is most conducive to maintaining a steady tempo. This will help to determine the necessary delay conditions to support networked musical performance (which may be over long distances or in adjoining rooms). Humans performed significantly better than a simple model of a memoryless instantaneous reaction. 1

Abstract—The complex nature of distributed networkbased musical performance served as the starting point for the Stanford University SoundWIRE group’s 2008 collaboration with Peking University in Beijing, China. In planning and executing the multi-ensemble networked concert entitled “Pacific Rim of Wire ” at Stanford on April 29, 2008, musicians and engineers from Stanford and Beijing undertook issues—technical and musical—ranging from the use of incompatible networking address protocols to the synchronization of performers, human and computer, across a 6000 mile span of network. This paper outlines the technical and musical strategies employed to support the production’s demands, as well as specific methodologies employed for the realization of Terry Riley’s In C. I.

The culture of laptop improvisation has grown tremendously in recent years. The development of personalized software instruments presents interesting issues in the context of improvised group performances. This paper examines an approach that is aimed at increasing the modes of interactivity between laptop performers and at the same time suggests ways in which audiences can better discern and identify the sonic characteristics of each laptop performer. We refer to software implementation that was developed for the BLISS networked laptop ensemble with view to designing a shared format for the exchange of messages within local and internet based networks.

Abstract not found