Physical Computing Ensemble

A Digital Music Ensemble Which Highlights Performer Interaction

Successful collaboration within an ensemble depends on the ability to perceive and react to each other’s actions. In the Physical Computing Ensemble we place this collaborative process front and center.

A web of interwoven social relationships are enacted in any musical performance. The goal of the Physical Computing Ensemble (or PCE) is to investigate how the design of a digital performance system shapes the ways these relationships come into being. To do this, we embed collaborative performance practices into three aspects of the ensemble— the structure of the digital performance system, the ways in which performers interact with the system, and the composition of musical materials.

“Physical Computing is about creating a conversation between the physical world and the virtual world of the computer.” — O’Sullivan and Igoe, Physical Computing: Sensing and Controlling the Physical World with Computers.

The computer algorithms used in artistic performance are frequently hidden from both the performers and audience. The PCE uses wireless gestural interfaces in order to make the performers’ interactions with these algorithms visually perceptible. This not only helps to convey the gestural origins of the computer-generated sound, but also provides crucial information regarding the musical intentionality of the performer, information which provides an essential tool for musical collaboration within the ensemble.

The PCE uses metaphors as the basis for gestural interaction with the computer

These metaphors provide a shared basis for understanding how to interact with an algorithm as well as how to interpret the results of the interaction. Metaphors used by the PCE include interacting with physical objects (throwing sound or skipping stones), performing with musical instruments (drumming), and interacting with sound itself (drawing audio waveforms).

Three members of the PCE drawing waveforms in the air. When performers utilize the same performance metaphor, it is easy to perform in synchrony.

The use of metaphors that could be expanded to encompass multiple performers suggested a variety of collaborative performance techniques. One approach is to share the control of sound processes between performers, so one performer controls rhythmic elements and the other controls timbre. Another approach is to metaphors based on social interaction, such as playing catch.

Video Documentation

Skipping Stones from Ian Hattwick on Vimeo.

Just Continue to Move from Ian Hattwick on Vimeo.

Triangulation from Ian Hattwick on Vimeo.


The Physical Computing Ensemble: Yunxiang Gao, Chris Lavender, Josh Ottum, David Resnick, Randall Smith, Kevin Zhang.
Ensemble Direction and Composition: Ian Hattwick
Video documentation by Matias Vellutini.


Hattwick, Ian (2011). “Face to Face, Byte to Byte: Approaches to Human Interaction in a Digital Music Ensemble”. MFA Thesis, University of California, Irvine.  
Abstract & Download

Hattwick, Ian and Kojiro Umezaki (2012). “Approaches to Interaction in a Digital Music Ensemble”. In: Proceedings of the International Conference on New Interfaces for Musical Expression. Ann Arbor, Michigan, USA.
Abstract & Download

Hattwick, Ian and Kojiro Umezaki (2012). “An Approach to Collaborative Performance in a Digital Music Ensemble”. In: Proceedings of the 1st Symposium on Laptop Ensembles & Orchestras. Baton Rouge, Louisiana, USA, pp. 109-110.
Citation and Download


UCLA Game Lab Carnival (May 19, 2011). Los Angeles, California.

Ian Hattwick’s MFA Recital (April 22, 2011). University of California, Irvine.