Exploring New Perspectives in Network Music Performance: The DIAMOUSES Framework

This article reports on the recent results of a research and development project on network music performance (NMP), named DIAMOUSES. DIAMOUSES is more than a standalone application for real-time exchange of audiovisual streams through the network, as it forms an open framework that aims to enable a wide range of applications and services for intuitive music expression and collaborative performance among geographically separated musicians. The realization of the DIAMOUSES open framework for NMP addresses several technological issues and contributes to the solution of a number of problems relating to human perception and human-computer interaction. It also contributes to the establishment of social connections between peers who collaborate through networks in which music is dynamically created, negotiated, and exchanged on the fly. This article describes DIAMOUSES in terms of technical orientation and validation, as well as in terms of user experience as revealed through a series of empirical studies. Collectively, these results provide useful insights into a variety of research questions on NMP and into a number of issues pending further attention.

Introduction

Physical proximity of musicians and co-location in a physical space are typical pre-requisites for collaborative music performance. Despite technological advancements and the proliferation of the Internet, networked music performance has still remained a challenge. The main technological barriers to implementing realistic NMP systems concern the fact that these systems are (1) highly sensitive in terms of latency and synchronization, because of the requirement for real-time communication, and (2) highly demanding in terms of bandwidth availability and error alleviation, because of the acoustic properties of musical signals. Latency is the most important hurdle to be dealt with, as it is introduced throughout the entire process of capturing, transmitting, receiving, and reproducing audio streams. Existing latency may be due to hardware and software equipment, network infrastructures, and the physical distance separating the communicating musicians. Even worse, latency variation, referred to as network jitter, forms an additional barrier in ensuring smooth and timely signal delivery. Moreover, an additional challenge relates to the actual experience of collaborative NMP and the value resulting from making this practice a virtual endeavor in cyberspace. Specifically, networked media may facilitate mechanisms such as sharing, feedback, and feed-through, thus catalyzing not only how music is produced and marketed but also how it is conceived, negotiated, made sense of, and ultimately created.

Presently, the majority of NMP systems that have been developed and explored are working on the technical challenges of NMP. Although a few of these systems manage to reduce latencies to the minimum possible value, none can actually guarantee timely—within certain limits—exchange of audio streams over large geographical distances. DIAMOUSES does not offer any major novelty in this regard, as it turns out that current technology cannot cope effectively with the geographical dispersion of performers in NMP scenarios. Nevertheless, despite the compromise with the inevitable physical and technological obstacles, DIAMOUSES proceeds one step further to provide a framework that we believe will have, in affordable technological conditions, a greater impact on forming community networks for music performance.

The main idea of the DIAMOUSES approach originates from the fact that music performance may occur in different contexts and for various purposes, such as live concerts, improvisation and jam sessions, recording sessions, interactive compositional sessions, music lessons, and master classes. Clearly, different contexts of use raise different requirements, both in terms of the underlying technological infrastructures and in terms of the interaction practices that must be supported. This is evident from the fact that research in different music performance contexts brings up significantly different issues and research priorities. For instance, in live music performance the key research issue is timely and accurate delivery of audible streams (Cáceres and Chafe 2009). However, in remote music-learning scenarios the research focus is on providing appropriate pedagogical paradigms and on exploring methods for the evaluation of student progress (Ng and Nesi 2008). Furthermore, in collaborative music composition, a key challenge is to represent musical events effectively and to devise appropriate symbolic musical notations (Hajdu 2006). DIAMOUSES presents a different angle by facilitating a variety...