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The live algorithm performance of “Tactical Temporalities” is a study in

minimalist rhythmical structures. The work is a semi-improvised musical

performance that is a practical outcome of research into musical structures

and their succinct description as computational algorithms. The work focuses

on subtle shifts in musical texture designed to induce an engaging but largely

uninterrupted flow of attention underscored by a consistent trance-like pulse

that affords ‘dancability’ in the Algorave context for which the work was first

created and presented at xCoAx 2014 (the Second conference on

Computation, Communication, Aesthetics and X) in Portugal. Elements of the

algorithm are accessed for modulation and variation by the performer via

touch screen interface and on-the-fly code rewrite. These include sound

timbre, rhythmic complexity, melodic contour, harmonic stability, textural

density and more. As is typical with a live coding performance the music is

described and managed as a textual representation in a general purpose

computer programming language.

The music is pulse-based and, in keeping with Western music theory, the

algorithms exploit the fact that durations are generally simple multiples or

divisors of a pulse. In music psychology the phenomenon of pulse, and

durations that are simple ratios of pulse, have been demonstrated to exist

outside of any cultural music context by various ‘tapping’ tests (e.g., Fraise

1984). This performance leverages these simple mathematical and perceptual

properties of musical rhythm to create and vary onset and durational

characteristics of musical parts.

Live algorithm performances challenge our understanding of creative

agency—the opportunities and responsibilities for decisions and actions in

creative activities—which is reshaped by the live coding relationship with the

computer where creative control is shared with a semi-autonomous computer

system. The interactive relationship established in this performance where the

computer is a musical instrument is differentiated from acoustic instrumental

performance, where the ‘material agency’ of the technology is usually fixed

prior to performance. The Live Coding context allows the performer to

experiment with what Pickering (1995) refers to as the “dance of agency” and

is a example of emerging digital arts practices that explore what Picking

suggests is a fundamental aspect of the human condition.

The work was originally programmed in the Impromptu environment, but was

ported in 2015 to Extempore (extempore.moso.com.au). Algorithmic

parameters are manipulated through code and a MIDI control surface during

live performance as a way of guiding the large scale temporal structure.

Sounds are generated by various virtual synthesizers and samplers.

xCoAx 2014 - 2014.xcoax.org

Fraise, P. (1984). Perception and Estimation of Time. Annual Review of

Psychology, 35, 1–7.

Pickering, A. (1995). The Mangle of Practice: Time, Agency and Practice.

Chicago: The University of Chicago Press.