Karlheinz Essl

Portrait KHE

Champ d'Action

realtime composition environment for computer-controlled ensemble
1998

Commissioned by the ensemble Champ d'Action (Antwerp, Belgium)


Basics | About | Setup | Notation | Structures | Literature | Reviews | Performances


Extreme Sight-Reading
Real-Time Music Notation in Live Performance

In Karlheinz Essl's Champ d'Action (1998), players in a chamber ensemble improvise, guided by notation that they read from laptop computer screens. The notation includes both graphical and textual elements with a set of symbols to indicate playing styles (such as clouds, points, trills, and drones); text specifiying variations on those styles; and "global parameters" indicating phrase und rest durations, pitch registers, and timbre.

One conductor initiates triggers on a server. Each trigger toggles the state of a single player between tacet and active; tacet players preview a new notation segment, while active players begin improvising based on that segment. The conductors's role is simply to send triggers; stochastic software algorithms, operating autonomously, decide to whom a trigger is sent and how the trigger changes the notation.

Essl's work creates a feedback loop in which the algorithm's notation influences how the musicians play, the musicians' sound influences how the conductor triggers the algorithm, and the conductor's triggers influence the timing and pacing of the algorithm's notation. The audience follows thsi process by watching the conductor and listening to the musicians as they enter and exit the texture and change their improvisation styles. They do not directly perceive the software's output - only its effect on the music the ensemble plays.

(...) Works employing real-time notation, such as Karlheinz Essl's Champ d'Action, use unconventional graphical notation to guide the improvisation of performers by specifying pitch registers, rhythmic density, contours, and other more abstract information. In such works, the musicians, free from the need to accurately sight-read difficult passages in concert, can focus more on expressing themselves musically and creating cohesive large-scale phrases in consort with the rest of the ensemble.

Jason Freeman: Extreme Sight-Reading, Mediated Expression, and Audience Participation: Real-Time Music Notation in Live Performance Music; in: Computer Music Journal, 32:3, pp. 25-41 (2008)



About

Animation Champ d'Action is a meta-composition for an instrumental ensemble of 3 - 7 soloists. The choice of the instruments is free. The premiere was played by an ensemble consisting of bass clarinet, trombone, cello, percussion and sampler.

The musicians do not reproduce parts of a fixed score. Instead of playing a pre-fabricated text from note sheets, they are viewing computer monitors which display playing instructions on the fly. The musicians are improvising those structures according to the given parameters.

Instead of being a fixed work, this piece should be viewed as a meta-composition which unfolds itself in a completely unforeseeable manner during the performance. It provides a wide, yet demarcated "field of possibilities" (another meaning of "champ d'action") which is explored by the musicians during the performance.

Although the piece is composed of independent parts, the aim of the musicians should be to create relationships by listening and reacting to the sounds that are produced by the other players which could lead to dramatic and extremely intense situations.

The notation which is displayed on the computer screens is generated in realtime by a computer program written in MAX. Whenever an external "trigger" is received by the central computer (the "master"), it will change the notation only for one musician at a time. These "triggers" can be either given by a conductor (or two sub-conductors which does not see each other) or by an external source (f.i. triggers sent by telephone or the Internet).


Photo from the premiere


Live concert at the Austrian Radio (6 Oct 1998) with:

Burkhard Stangl (e-git), Werner Dafeldecker (double bass), Gene Coleman (bass clarinet), Radu Malfatti (trombone), Elisabeth Flunger (percussion), Mary Oliver (violin), Richard Barrett (sampler) and Karlheinz Essl (conductor)

photo: © 1998 by Eva Wohlgemuth



Setup

The musicians are situated on stage, each of them equipped with an Apple Macintosh computer (preferably, a PowerBook). These machines (lets call them "monitors") are connected via MIDI to a central computer (the "master") which receives the external triggers and controls the other computers. Whenever a trigger is sent to the central computer, it will passed to one of the connected computers according a specific random algorithm.


Photo


Each "monitor" has two states and - like a toggle - is constantly switching between them whenever it receives a trigger: in passive mode it will display the notation for the next structure to be played, partly covered by a big fermata sign. It indicates that the musician has a pause, and provides the possibility to prepare himself for the next active phase which is indicated when the fermata sign is removed.


Fermata Sign


By this mechanism, only one of the musicians will either become active or passive whenever a trigger is sent to the central computer which will result in slight changes of the overall structure.

Here is an example:

The beginning: all musicians are in passive mode and not playing at all.

Graphic

Now the first trigger was received and sent to the 3rd player who will start playing the structure that is displayed on his monitor:

Graphic

The next trigger makes the 1st player play:

Graphic

Now the 4th musician enters:

Graphic

The first player stops playing and prepares himself for the next structure:

Graphic

The 3rd musician stops - only the 4th keeps on playing:

Graphic

etc. etc.



Notation

This piece has no score. It is built of independent parts which are generated by a computer program in realtime. Each part uses of 8 different types of structures as its basic material. The parameters of these structures are changed algorithmically during the piece.

This is an example of the notation of a POINT structure :


POINTS POINTS


Graphic long

middle

short

Graphic long

middle

short

Graphic high

middle

low

Graphic pitched

semi-pitched

unpitched

phrases

pauses

registers

sounds

types: pre / post
periodicity: 4



Click on the button above or on this link to see the notation of
another randomly selected and specified structure.

NB: To view this page your browser must support JavaScript.



Global parameters

Each structure is determined by the same 4 global parameters:


parameter description
phrases duration of musical phrases
pauses duration of rests
registers subdivisions of instrumental range
sounds quality of sounds



Each global parameter is subdivided in three regions. Only the selected regions (specified by colored fields) have to be taken into account.

Graphic long

middle

short

Graphic long

middle

short

Graphic high

middle

low

Graphic pitched

semi-pitched

unpitched

phrases pauses registers sounds


In this example you have short phrases alternating with long pauses. The instrumental range goes from low to middle, and the sounds are pitched and unpitched.



Structures

Champ d'Action is composed of 8 different types of structures. Each structure has its own characteristic appearance and is determined by a set of individual parameters. If more than one parameter value is shown the player can make choices.

By clicking on one of the structures listed below you'll get more information about the appearance and parameters:


Points POINTS
isolated "punctual" events
Planes PLANES
sustained sounds of different pitches and durations
Drone DRONE
a repeated single sound, swelling and fading
Figures FIGURES
grace-note figures, glissandi, espressivo gestures etc.
Solo SOLO
freely improvised musical phrases using material from other structures
Clouds CLOUDS
short sounds distributed in time and space producing a cloud-like (mass) texture of a certain shape and density
Trills TRILLS
rapid permutation of a number of sounds
Repetitions REPETITIONS
repetitions of a single sound with various amounts of pauses ("excavations")



Literature



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Updated: 2 Apr 2016