Karlheinz Essl

Champ d'Action

for computer-controlled ensemble

New Millenium: New Music: Karlheinz Essl (John Richey)
in: Computer Music Journal, 24:1 (2000)

On 18 April 1999, the Chicago Cultural Center presented two works by Austrian composer Karlheinz Essl as part of its New Millenium: New Music series. Both compositions provided frameworks for improvisation by members of two Chicago groups, Ensemble Noamnesia, and the Association for the Advancement of Creative Musicians (AACM).

Mr. Essl, who teaches computer-aided composition at the Bruckner Academy in Vienna [recte: Bruckner Conservatory in Linz], conducted Champ d'Action (1998) by generating verbal and graphic instructions and sending them over a network to laptop computers stationed in front of each performer. Tending a multibutton pad, he sent signals to a central computer loaded with a program he wrote using MAX software. The program transformed the signals into directions for the performers - generally, when to play and in what character - who took time to consider, then began improvising. A detailed technical description of Champ d'Action can be found on the composer's ambititious World Wide Web site (http://www.essl.at/works/champ.html).

Champ d'Action was performed twice by members of Ensemble Noamnesia, first by a quartet of winds, and then by a mixed trio. The quartet's performance had mostly a nice quiteness to it, though it would rise to an occasional squawk. Lisa Goethe on flutes, Kyle Bruckmann on English horn, Gene Coleman on bass clarinet, and Jerry Ruthrauff on soprano saxophone all showed inventivness and sensitivity on the others' playing. Mr. Essl's direction kept the texture and the character of the music diverse, and kept Ms. Goethe involved even when her laptop gave out. More enjoyable still (though the opinion ssemed to disappoint Mr. Essl who took greater care perplanning the quartet) was the trio of Mr. Coleman on bass clarinet, Michael Cameron on double bass, and Steve Butters on percussion. The three, all resourceful improvisers, wrung a variety of colors from their instruments, their experience playing together highly evident. The joining of dissimilar instruments created an entirely different effect from the homogeneity of the quartet, demonstrating the flexibility of Mr. Essl's meta-composition, as he labels it. (...)

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

(...) Karlheinz Essl’s Champ d’Action (1998) offers a simple illustration of this merged expression. 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 specifying variations on those styles; and “global parameters” indicating phrase and rest durations, pitch registers, and timbre. One or more conductors initiate 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’ 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 conductors trigger the algorithm, and the conductors’ triggers influence the timing and pacing of the algorithm’s notation. The audience follows this process by watching the conductors 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.

Many other 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. And when real-time systems use graphical notation in lieu of staff-based notation to represent dense musical passages, they also circumvent the limitations of automated notation layout algorithms, which must weigh flexible layout rules against graphic design sensibility (...).

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Updated: 12 Aug 2008