Controlling Interactive Music Performance (CIM)
Andrew Brown, Toby Gifford and Bradley Voltz
Queensland Conservatorium of Music, Griffith University
andrew.r.brown@griffith.edu.au, t.gifford@griffith.edu.au, b.voltz@griffith.edu.au
Abstract
Controlling Interactive Music (CIM) is an interactive
music system for human-computer duets. Designed as
a creativity support system it explores the metaphor
of human-machine symbiosis, where the phenomenological
experience of interacting with CIM has both
a degree of instrumentality and a sense of partnership.
Building on Pachet’s (2006) notion of reflexivity,
Young’s (2009) explorations of conversational interaction
protocols, and Whalley’s (2012) experiments
in networked human-computer music interaction, as
well as our own previous work in interactive music
systems (Gifford & Brown 2011), CIM applies an activity/relationality/prominence
based model of musical
duet interaction. Evaluation of the system from both
audience and performer perspectives yielded consensus
views that interacting with CIM evokes a sense of
agency, stimulates creativity, and is engaging.
Description
The CIM system is an interactive music system for use in
human-machine creative partnerships. It is designed to sit at
a mid-point of the autonomy spectrum, according to Rowe’s
instrument paradigm vs player paradigm continuum. CIM
accepts MIDI input from a human performer, and improvises
musical accompaniment.
CIM’s behaviour is directed by our model of duet interaction,
which utilises various conversational, contrapuntal and
accompaniment metaphors to determine appropriate musical
behaviour. An important facet of this duet model is the notion
of turn-taking – where the system and the human swap
roles as the musical initiator.
To facilitate turn-taking, the system includes some mechanisms
for detecting musical phrases, and their completion.
This way the system can change roles at musically appropriate
times. Our early implementation of this system simply
listened for periods of silence as a cue that the human performer
had finished a phrase. Whilst this method is efficient
and robust, it limits duet interaction and leads to a discontinuous
musical result.
This behaviour, whilst imbuing CIM with a sense of autonomy
and independence, detracts from ensemble unity and
interrupts musical flow. To address this deficiency, we implemented
some enchronic segmentation measures, allowing
for inter-part elision. Inter-part elision is where phraseend
in one voice coincides with (or is anticipated by) phrasestart
in a second voice.
In order to allow for inter-part elision, opportunistic decision
making, and other synchronous devices for enhancing
musical flow, we have implemented some measures of musical
closure as secondary segmentation indicators. Additionally
these measures guide CIM’s own output, facilitating
generation of coherent phrase structure.
The evaluation procedure
Our evaluation process involved six expert musicians, including staff and senior students at a
University music school and professional musicians from the State orchestra, who performed
with the system under various conditions. The setup of MIDI keyboard and computer used for
these sessions is shown in Figure 5.
Figure 5: A musician playing with CIM
Participants first played a notated score (see Figure 6). Next they engaged in free play with the
system, giving them an opportunity to explore the behaviour of the system. Finally, they
performed a short improvised duet with the system. The interactive sessions were video
recorded. Following the interactive session each performer completed a written questionnaire.
Figure 1: A musician interacting with the CIM system
<references_biblio/>
References
Gifford T & Brown A R (2011). Beyond Reflexivity: Mediating
between imitative and intelligent action in an interactive
music system. In: Proceedings of the British
Computer Society Human-Computer Interaction Conference
2011, Newcastle Upon Tyne.
Pachet F (2006). Enhancing individual creativity with interactive
musical reflective systems. In Musical Creativity:
Current Research in Theory and Practice. Wiggins G &
Deliege I (eds) London: Psychology Press
Whalley I (2012). Internet2 and global electroacoustic music:
Navigating a decision space of production, relationships
and languages. Organised Sound 17(01):4-15
Young M (2009). Creative Computers, Improvisation and
Intimacy. In Boden M et al (eds) Dagstuhl Seminar Proceedings
09291: Computational Creativity: An Interdisciplinary
Approach
Proceedings of the Fourth International Conference on Computational Creativity 2013 221