Performance Practice
of Electroacoustic Music

Georg Friedrich Haas

Ein Schattenspiel


Ein Schattenspiel for piano and electronics was composed in 2004 and first performed on 25 April 2004 at Funkhaus Wallrafplatz in Cologne (WDR) with Siegfried Mauser, piano.

Georg Friedrich Haas’ recurring interest in electronic means is is apparent in six works from the last 17 years featuring different approaches; the 4th String quartet (2003) followed by Ein Schattenspiel (2004), the expansive piece Les temps tiraillés for two violas, bassoon and electronics (2008) realised at IRCAM and premiered in collaboration with the choreographer Myriam Gourfink, the ensemble pieces … und … for chamber ensemble and electronics (2008-09) and Introduktion und Transsonation for 17 instruments and tape (2012) “with sound material from experiments by Giacinto Scelsi” and the 7th String quartet (2011). In each piece the use of electronics touches on constitutive aspects of Haas’ instrumental works such as harmonic structure and microtonality, timbre and the reference to historical sources.

The live electronic systems used in the 4th String quartet and in Ein Schattenspiel share the same principle of microtonal transposition based on playback speed and delay. In Ein Schattenspiel this generates a canon structure of sorts: the signal of the live piano is recorded and played back at a slightly higher speed (factor 33/32) in order to achieve a transposition of approximately 50 cents (quarter tone) and with an initial delay of 24 seconds. Due to the higher playback speed, the delay between live piano and electronic “shadow” (the title Ein Schattenspiel means “shadow play”) gradually decreases, eventually becoming zero at the end of the piece. Haas likens this configuration to the image of the performer being confronted by his own past: “The player of the piece is constantly faced anew with what he has just played. The live electronics confront him with his own history, which eventually catches up with him.” [quoted from Muxeneder, Werkeinführung]. The idea of “shadows” resulting in a quarter tone structure may have conceptual roots in Tristan Murail’s idea of differential tones as shadows, a concept used by Haas in his piece Schatten… durch unausdenkliche Wälder from 1991. [Haselböck 2019, 5:00 – 7:10] Different sound typologies are used to engage the pianist in a microtonal interplay with the delayed transposition. The piece opens with sharp low impulses and overtone resonances. In the 1st section cascades of chords, trills and interval repetitions are carefully disposed in order to produce polyphonic textures and complementary sequences. In the 2nd section the pianist is requested to improvise based on prescribed pitch groups. This leads to slightly accelerating sequences of chord repetitions in the 3rd section which reappear in the 5th (and last) section.

The long 4th section in between creates a strong harmonic contrast. Sequences of chords and arpeggios mostly based on seventh chords in different inversions overlap with their electronic repetition a quarter tone higher. The bass tone strides upwards in quarter-tone steps and the live piano restarts the cycle with exactly the same figures after a major seventh, which, seen on a large scale, corresponds to a half tone step downwards. The piece ends with clusters in the extreme registers of the instrument.

Besides the canonic principle, a major formal characteristic of Ein Schattenspiel is the sequential shifting of harmonic structures based on stacked intervals, e.g. tritone and fourths in the first part, major sevenths in the second or augmented octaves in the 3rd and 5th sections. The electronically delayed transposition fills the spaces in between or creates microtonal mixtures. It is well known that Haas’ use of equal-tempered interval structures is strongly inspired by the works of Wyschnegradsky. [cf. Hasegawa 2015] A prominent feature in Ein Schattenspiel is the “perfect” division of near-octave intervals (diminished and augmented octaves) in equal intervals (5.5 and 6.5 halftones respectively) due to the upward transposition by a quartertone, producing so called “Wyschnegradsky chords”. [cf. Morrison 2019] These structures clearly contrast with the almost tonal character of the sequences in the 4th section, which can be understood as overtone related chords projected onto the chromatic grid.

The ascending tendency of the piece owing to the upwards quarter tone transposition is counterpointed by sequential progressions in the opposite direction. These result in sequential movements across the register, at some points at the same time ascending and descending. Besides the abovementioned case in the 4th section this can also be observed in the chord sequences of the 2nd and 5th sections. The canon device is further used to create some paradoxical situations as in the 2nd section (e.g. page 2, 2nd system), where the live piano imitates the delayed piano after a sixteenth note, thus becoming the “shadow” of the “shadow”.

These formal devices make clear references to preceding pieces such as in vain (2000) for large ensemble. The opposition or clash between different microtonal systems, such as scale based equal-tempered, overtone based chords or aleatorically generated microtones, in combination with paradoxical temporal and harmonic movements (Penrose staircase, Shepard tone) has been a major feature in Haas’ works since the turn of the millennium. Beyond the specific symbolism these forms might have in other pieces, their use in Ein Schattenspiel reflects the composer’s interest in perceptual phenomena and in the link between harmonic and temporal systems and processes. In Ein Schattenspiel the live electronic system provides such a harmonic-temporal link based on two of the simplest and most fundamental transformations in electroacoustic music: faster playback and delay.

The major challenge for the pianist is to find a temporal articulation – which of course will be slightly different in each performance – within the fixed time frame imposed by the delay system. The performer is thus constantly confronted with actions taken in the past, requiring him or her to respond to them in the moment, being aware of what will happen later.
The live electronic performer on the other hand should find a setup that allows for a natural sounding fusion of the live and electronic sound.


Performance Materials:

a. Score: Universal Edition, 2004 (UE 32945)

The printed score is copied on demand and delivered with a CD-ROM containing the patch for the electronic part and a documentation written by Johannes Zmölnig of the Institute of Electronic Music and Acoustics at the University of Music and Performing Arts Graz, Austria. The live piano and the electronic part are notated on separate systems. The electronic part is notated untransposed.

b. Other materials:

Software (Patch)


Source: Universal Edition, Vienna (included on CD-ROM distributed with the score)

Date: 29 March 2004
Author: Johannes Zmölnig / IEM Graz
Software: Pure data
System: Windows and Linux
Remarks: Comes with a manual by Johannes Zmölnig
File: MAIN.pd


Source: Florian Bogner
Date: 15 February 2018
Author: Florian Bogner
Software: MAX
System: MacOS
File: fbog-schattenspiel03.maxpat

Source: ICST
Date: 2019
Authors: Florian Bogner, updates: Peter Färber/Germán Toro Pérez
Software: MAX
System: OS
Updates by Peter Färber, 29 May 2019:
-Midi pedal integration allows the musician to start and stop the patch
-Click for the first 35 seconds

Update by Germán Toro Pérez, recording session, 22 February 2020:
-Fade out when stopping the patch

fbog-schattenspiel03 20190529.maxpat


Editorial instructions

The only remark concerning the realisation of the electronics is found on page 1:

“Wiedergabe des Klavierklanges um einen Viertelton aufwärts transponiert zunächst um 24 Sekunden zeitverzögert, durch die Transposition ist die Wiedergabe ein wenig beschleunigt. Keine weiteren elektronischen Veränderungen – möglichst genau wiedergegebener Klavierklang”

[“The piano sound is played back a quarter tone higher with an initial delay of 24 seconds; because of the transposition, the playback is somewhat accelerated.
No further electronic processing –piano sound to be reproduced as precisely as possible”]

The score contains numerous indications on the coordination/synchronisation of the live and electronic parts.

The accompanying documentation by Johannes Zmölnig contains only information about the patch: installation, operation and troubleshooting. It contains no information about the sound diffusion system (microphones and loudspeakers), its disposition or performance. The piano part is recorded with microphones and fed to the live electronics as stereo signal.
[cf. documentation, p. 2]

Delay time and duration
The most remarkable issue is the divergence between score and manual concerning the initial delay between the live piano and its “shadow” transposed a quarter tone upwards and the resulting maximum duration of the piece.

The manual indicates a delay of 27 seconds and a total duration of approx. 17 minutes. [Manual, “Zusammenfassung”] A delay of 24 seconds, as prescribed in the score, results in a possible maximum duration of approximately 14 minutes. This difference has major consequences. It can be assumed that the delay prescribed in the score is correct. A longer initial delay would require slower tempi and would diminish the characteristic drive of the piece caused by the continuous acceleration, most clearly perceived in the last section.

It is important to underline that the effective duration of a performance is not defined, but merely limited by the system. Starting with 24′ delay and due to the faster playback needed for a 50c transposition, the system takes 14:03 minutes for the delay to decrease to zero. Nevertheless, the text can be realised faster, finishing with a small delay between live piano and shadow, as is mostly the case. A longer duration would lead to a break since the system will stop playing when the delay reaches zero. The most challenging issue for the performer is thus to take decisions about tempo and duration of rests and free sequences, which will necessarily affect the synchronisation and superposition with the electronic part. (see the remarks by Dominykas Girčius below [Performance report]

As stated above, the only indication related to sound projection appears at the beginning of the score, calling for a natural (“precise”) reproduction of the piano sound. [Score, p. 1]

Performance report

The performance was realized on 27 June 2019 at ZHdK’s main concert hall (Toni Areal, Zurich) with Dominykas Girčius, piano, Leandro Gianini, sound engineer, and Germán Toro Pérez, sound projection.

The patch provided by the publisher only works on Windows and Linux systems. In this instance, however, a Max/MSP patch written by Florian Bogner and running on MacOS was used.

A main question in performing Ein Schattenspiel concerns the role of leakage. Since the system records all signals present in the room, the “shadow” will be recorded and played back later as well. Therefore, loud events, as the first chords of the piece, can be audible in 2nd and 3rd generation feedback.

We first tried to reduce this effect. Different microphones in different positions such as EV RE20, Neumann TLM103, Schoeps cardioid, AKG C414 and Helpinstill pickups were used in combination with different loudspeaker positions. The results were recorded and the recordings compared with the live instrument. While with some configurations it was possible to reduce the leakage, the quality of the signal would also deteriorate. It was decided not to compromise at the expense of sound quality – in accordance with the main instruction – and to accept the leakage as a feature of the piece.

Another challenge lay in achieving a full, massive sound for the first fortissimo chords of the piece while revealing enough detail in the faster and more dense passages. We finally combined two stereo sets of microphones, one closely (AKG C414), and one more distantly positioned (Schoeps MK4). To minimise leakage of the first chords played, the input of the patch was muted when the electronic part was playing alone during the first page of the score (second system, first chord of the “shadow”). In order to optimise sound quality, the signals of the two close microphones were then processed with a dynamic equaliser.

Another major issue is the placement of the speakers. In the rehearsal space, which was not large, we experimented with the speakers placed behind the piano, however missing presence and direction. It was finally decided to place the two main full range speakers in front of and as close as possible to the piano. This setup worked well in the rehearsal space; however, results were not optimal in the concert venue. Indeed, the signal was almost too directional. We attempted to lend more presence to the electronic transposition, adding two loudspeakers at the sides and sending a softer signal. Two Genelec 1038 BP speakers in front of the piano as a main system and two K&F Gravis on the sides were used. (s. Figure I)


Fig. I. Speaker setup. The encircled speakers were added for the second performance.
Fig. I. Speaker setup. The encircled speakers were added for the second performance.


Sound projection
The overall intention was to obtain a perfect dynamic balance between the live piano and the “shadow” and to approach the sound of the latter as closely as possible to the live instrument. In this way, the microtonal sound would better blend in, and the audience would not always be able to distinguish between both layers. It is important to keep in mind that the differences in dynamic and sound quality depend on the register and the dynamics of the piano performance. Sometimes the soft parts would be too soft and the loud parts too loud, especially between pages 10 and 20 of the score. It was therefore necessary to manually drive the output of the electronic part (+- 5 dB) during the performance.

In the beginning, a small monitor speaker for the pianist was used. This was then abandoned in favour of headphone monitoring. With headphones, the piano player could better hear the live transformation, and it was possible to give him a click for the beginning of the piece. Headphone monitoring was provided via the AVIOM system, mixing direct piano, electronic “shadow” and click. The click was only given for the first 35 seconds. (s. below, Remarks by Dominykas Girčius)

We had the opportunity to perform the piece again shortly after the first performance with the same setup and team, and at the same venue. This performance took place on 4 October 2019. Two additional loudspeakers and different signal routing were used, the goal being to better approximate the sound of the piano and its “shadow” in this large space.

The main speakers received the dry signal. The second set of speakers received a wet signal from a first reverb (Hall 1), and the third set of speakers received a wet signal from a second reverb unit with longer decay time (Hall 2). In this performance, it was less necessary to adjust the levels of the live electronic output from FOH, possibly due to the more consistent playing of the musician or the better sound setup.

Remarks by Dominykas Girčius

In Ein Schattenspiel a major challenge for the pianist is the organisation and control of the musical material over time. The performance needs to be thoroughly planned but the outcome must be expected to be slightly different each time. The pianist has to be able to adjust his or her playing without distorting the overall performance concept.

Three musical layers must be considered at every point of the piece: past, present and future. One is challenged to remember how the antecedent passages were played in order to be together with the delayed “shadow” and at the same time to pursue the musical thought in such way that the upcoming musical material will also make sense and sound natural in combination with a new “shadow”.

But synchronisation is not the only challenge. Dynamics and timbre also need to be considered and adjusted, because in many places the phrases are built by combining new material with the delayed one. Accordingly, the pianist should ideally feel as if playing in a piano duo.

From a technical point of view, I found it helpful to play with headphones on both ears mixing the signal from the microphones with the delayed signal from the patch. Other possible combinations were distracting because of the timbre and time differences. Playing with headphones on both ears renders one somewhat unaware of the room acoustics, though. In this case, it is essential to record and analyse your performances frequently.

Selected Bibliography

Farthofer, Lisa (2007): Georg Friedrich Haas: „Im Klang denken”. Saarbrücken: Pfau.

Hasegawa, Robert (2015): Clashing Harmonic Systems in Haas’s Blumenstück and in vain. In: Music Theory Spectrum, 37 (2), pp. 204–223.

Haselböck, Lukas (2019): Lecture on Ein Schattenspiel held at ZhdK, 27 June 2019

Morrison, Landon (2019). Playing with Shadows: Reinjection Loops and Historical Allusion in Georg Friedrich Haas’s Live Electronic Music. In: Circuit, 29 (2), pp. 63–82.

Muxeneder, Therese: Werkeinführung, online: [last accessed on 17 February 2020]

Schematic Overview