Paper Session 3: Networked Performance
Chris Chafe (Stanford University), session moderator
Saturday, Nov. 19, 10:00am, CalIT2 Auditorium
10:00. Álvaro Barbosa, and João Cordeiro: The Influence of Perceptual Attack Times in Networked Music Performance
It is well known that Latency has a highly disrupting effect in musical practices, booth at the level of a performer’s own musical feedback and at the overall musical response resulting from a collaborative act. In musical communication over the Internet, one of the most promising approaches to minimize the constraints caused by extreme latencies is to adapt the musical practices according to perceptual audio features that influence the latency threshold for music performance. According to the information extracted from these descriptors, it is possible to shape the musical language at the compositional stage or at the performative level. Research has previously been conducted concerning the relation of this threshold with features such as the musical tempo and loudness. Nevertheless, further study remains to be done, particularly concerning the ability to synchronize delayed performances for different music expressive qualities related with performing technique at the level of individual notes. This paper presents a pilot study that suggests a better tolerance to communication latency, for musical pieces based on notes performed with slow attack sounds.
10:30. Alexander Carôt and Gerald Schuller: Towards a telematic visual-conducting system
Recent advances in networking technology (higher bit rates and lower transmission latencies) enable new applications where musicians can play together remotely, over the Internet. This application requires an audio coder which feature sufficient compression in order to avoid overloading a connection and delay jitter, and which also has a very low encoding/decoding delay. Often it is also desirable to have a visual connection, particularly for a conductor of an orchestra. But a parallel video connection often overloads a low delay connection, and usually also leads to more jitter and delay in the audio connection. Hence our approach is to design a special conductor transmission scheme, using a standard computer mouse, for this purpose. We found the data from this transmission scheme can be easily integrated in the audio data stream without affecting jitter and delay. Experiments showed that the conductor and the orchestra could tolerate round trip times of about 75 to 150ms, depending on the speed of the music.
11:00. Alain Renaud: Cueing and composing for long distance network music collaborations
Long distance network music collaborations beyond the ensemble performance threshold (EPT) as exposed by Schuett in 2002  where playability is affected beyond a round-trip network delay of 50ms calls for the development of cueing mechanisms that are methodical and linked to musical parameters. The cueing strategies involved in such musical interactions will depend on the type of repertoire played and the network distance (ND) between the nodes involved in the performance. This paper proposes a semi-standardized cueing framework for real time collaborations over the network with latencies of more than 50ms. The paper also explores a compositional methodology for creating network centric performances, which couldn’t occur outside of a networked situation.