PhDr. Michal Rataj, Ph.D. /CZ/ - composer, HAMU PRAHA – Academy of Music Prague

Ars Acustica Palmarum 2013 – 2015


PhDr. Michal Rataj, Ph.D. /CZ/ - composer, HAMU PRAHA – Academy of Music Prague


In this text I would like to present background visions and practical compositional and performance experiences, which have been developed over the past three years as part of liturgical art interventions on Palm Sundays at the St. Salvator Church, Prague.


The idea was to introduce different sound elements and performance aspects into a new contemporary liturgical music event, which would be part of the initiation of the Holy Week – Palm Sunday Liturgy. The choice of Palm Sunday as one of the crucial liturgies of the year is rooted in my engagement with Gregorian chant repertoire of this particular celebration as far back as the 1990s. As a musicology student I was able to conduct research on musical aspects of liturgical procession as they existed during medieval times. The research concerned not only musical material itself (texts, melodic settings, liturgical guidelines), but also the entire spatial and performance aspects of the liturgy occurring both outside and inside the church. The Palm Sunday procession has always been a performance event interconnecting elements of theatre, music, choreography and spatial composition. The immediate contrast of the “great joy” outside the church celebrating the approach of Jesus Christ to the city of Jerusalem and which breaks through the deep sorrow of the Passion Week inside the church has always had a powerful influence on me.


Several years ago series of artistic interventions were initiated at the academic parish of St. Salvator as part of Lent, produced by the Center for theology and art[1]. Adriena Šimotová, Václav Cígler, Norbert Schmidt, Jaromír Novotný, Stanislav Kolíbal, Michal Škoda (among many others) were artists who placed visual objects in the church space to interact with it as part of the “holy period” before Easter[2].


Almost three years ago a more ambitious visual intervention was produced in the church. Patrik Hábl replaced all the original baroque altar canvases inside the church with his mostly dark & gold paintings (monotypes). Upon entering the church for the first time to view them, I realized something was “wrong” but I could not tell what. The fantastic and hidden mixture of contemporary paintings on church altars along with the liturgical space (with its shapes, colors, shadows and period atmosphere) was somehow unreal. It spoke to me as a genuine symbiosis of the past and present.

When I met the curator, Norbert Schmidt, for the first time, I mentioned offhand, “It would be nice to have some music there, wouldn’t it?” Thus the first Ars Acustica Palmarum took place in 2013.


While considering the possible composition of such accompanying music, it became clear to me that it would be a mixed repertoire of traditional Gregorian chant and contemporary electroacoustic music. After several experiences employing chant elements as part of my concert compositions,[3] I started to develop dramaturgy based on the traditional Gregorian chant repertoire of Palm Sunday and newly composed short electro-acoustic sound compositions.


In order to bring together such different perceptual worlds as the Gregorian chant and contemporary sound performance, I decided to establish the original chant modality as the common denominator, which would be the basis for the harmonic structure for whatever would happen. These traditional chant tunes of Palm Sunday established the melodic and harmonic context for developing an entirely new sound world of liturgical music. The tunes employed were:

-          responsorium Ingrediente Domino (starts on E, tenor on G)

-          tractus Christus Factus Est (tenor on E)

-          responsorium Impropérium exspectavit cor meum (starts on C, tenor on G)

-          antiphona Pater, si non potest (starts in C, tenor on G)

-          psalm Deus Deus meus (starts on E, tenor on A)


I then asked a small group of musicians (every year different ones) with contrasting musical instruments to play along with the chant tunes in this emerging semi-improvised liturgical sound performance. I suggested that the performance would be controlled by two particular aspects:


-          chant modality and its melodic material

-          pre-produced electro-acoustic sound composition and real-time based sound transformation of acoustic instruments performed by myself.


During the performance, different sound elements are transmuted into new acoustic shapes, and on top of that, the resulting sound is diffused in an artificial acoustic space designated by a set of four loudspeakers, which are placed in a wide ambitus inside the church.


During three consecutive years, different acoustic settings were realized based on different interpretations of Gregorian chant tunes on one hand, and different ensemble constellations on the other:


2013[4] – a mixed male-female choir sang Gregorian tunes on the balcony without amplification (15 meters above peoples’ heads) while a performance of saxophone, acoustic guitar, kantele and live-electronic musicians took place to the left of the main altar surrounded by a four-channel loudspeaker setup.


2014[5] – a male choir sang Gregorian tunes with light amplification right next to the main altar, while viola da gamba (tuned to 440 Hz), cimbalom and a live-electronic performance took place across the central axis on the left side.


2015[6] – a solo male vocalist sang the entire Gregorian repertoire with regular amplification accompanied by violin, tabla, clarinet and a live electronic performance paired on several spots with the main organ improvisation back in the church. The third issue of the Ars Acustica Palmarum achieved not only a new quality in the sound integration of chant and sound performance inside the artificial space of electro-acoustic field, but also another spatial quality through interconnection with acoustic based organ across the entire church space.


Three Palm Sunday music interventions followed immediately the procession taking place outside the church. While people were entering the church, the performance basically followed the proprium order of the mass in five musical interventions:

1/ Introitus – the procession entered the church, people were spreading inside (Ingrediente Domino), a plain chant was followed by a sound performance,


2/ Tractus (Christus factus est)

chant only, in 2015 enhanced by light background sound composition,


3/ Offertorium (Impropérium exspectavit)

chant followed by sound performance,


4/ Communio (Pater, si non potest)

chant followed by sound performance,


5/Psalm Deus Deus meus

chant performance divided into psalm verses, each followed by dynamically increasing sound performance.


Common ordinarium missae (by Petr Eben, respectively Karel Bříza) was sung during the service, either with small positive organ in front of the church (2013, 2014) or accompanied by the main organ (2015).


In order to understand better the technological framework of the performance, let me briefly describe the primary specifications of the computer-based virtual instrument I played along with live musicians. The virtual instrument consists of a MAX-based[7] environment featuring live controlled

-          multichannel multi-sample player,

-          stochastic and spectral synthesizers,

-          real-time spectral resynthesis module (based on SDIF buffers),

-          multichannel live input delay chain,

-          live input granular synthesis engine.


Samples, spectral models and other sound material follow the chant modality and are ready to be articulated live using a Wacom tablet and some other peripheral controllers. As such, the virtual computer based instrument actively connects the live sound performance with other musicians. Their sound is captured by microphones and connected to an audio interface input. Each of these instruments can thus be transformed in real-time and acts as another sound level according to the material being stored / pre-produced inside the computer. Delay and granular synthesis are the main tools of sound intervention.


Four speakers were placed at four locations inside the church - two at the front part of presbytery, two in the middle at the cross axis of the church. The four speakers were not only responsible for creating a new spatial sound quality, but they also enhanced the acoustics of the church by a different type of spatial resonation.


During the first intervention in 2013, Gregorian chant parts of the performance were juxtaposed with electro-acoustic ones. The last issue in 2015 – on the contrary – featured a continuous mix of chant, ensemble and organ (even though the organist was forced to play one semitone higher because of the baroque tuning of the organ). This provided an entirely new experience to both performers and audience.


As our musical apprehension has developed over past couple of decades (particularly influenced by many inter-media aspects), we realize it is the power of electro-acoustic music language above all, which absorbs many different acoustic impulses, elements, techniques, aesthetics and excitements and it shapes them into completely new sound qualities. There are no longer male voice, violin, percussions or cimbalom acting as individual voices – they have been transformed into new sound semantics, which have been built both across centuries (old chant – traditional instruments – virtual electronic engines) and across spaces (liturgical, architectural, musical, grammatical, semantic).



This publication was written at the Academy of Preforming Arts in Prague as part of the project “Sensors As Musical Instruments” with the support of the Institutional Endowment for the Long Term Conceptual Development of Research Institutes, as provided by the Ministry of Education, Youth and Sports of the Czech Republic in the year 2014.







[1] Initiative curated & led by the architect Norbert Schmidt,

[2]An obvious inspiration of the main curator Norbert Schmidt by the Kunst-Station Sankt Peter in Cologne is noticable, viz e. g. Norbert Schmidt (ed.), Friedhelm Mennekes: Nadšení a pochybnost, Praha 2012.


[3]Oratorium Electronicum (2002), Corde, Lingua, Voce (2006), Invito (2008).

[4] Schola conducted by Filip Srovnal, soprano and tenor saxophones by Štěpán Škoch, kantele and live electronics by Jan Trojan.

[5]Schola conducted by Jiří Hodina, viola da gamba by Mélusine de Pas, cimbalom by Jan Mikušek.

[6]Solo voice by Jiří Hodina, violin by Slavomír Hořínka, tabla & clarinet by Tomáš Reindl, organ by Eva Bublová.

[7]Modular software environment for real-time based MIDI, sound and image processing,


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