Adaptive Parameters in Mixed Music

Introduction

During the last several years, the interplay between processed and acoustic sounds has been the focus of research at the department of music technology at NTNU. So far, the project “Cross-adaptive processing as musical intervention” has been mainly concerned with improvised music such as shown with the music of T-EMP. However, through discussions with Øyvind Brandtsegg and several others at NTNU, I have come to find several aspects of their work interesting in the world of written composition, especially mixed music. Frengel (2010) defines this as a form of electroacoustic music which combines a live and/or acoustic performer with electronics. During the last few years I have especially come to be interested in Philippe Manoury’s conception of mixed music which he calls real-time music ( la musique du temps réel ). This puts emphasis on the idea of real-time versus deferred time which we will come back to later in this article.

The aspect of the cross-adaptive synthesis project which makes the most resonance with mixed music is the idea of adaptive parameters in its most basic form. A parameter X of a sound, influences parameter Y of another sound. To this author, this idea can be directly correlated to Philippe Manoury’s conception of partitions virtuelles which could be translated into English as virtual partition or sheet music. In this article, we will explore some of the links between these concepts, and especially how they can start to influence our compositional practices in mixed music. A few examples of how a few composers have used adaptive parameters will also be given. It is also important to point out that the composers named in this article are far from being the only ones using adaptive parameters, they have done it in either an outstanding and/or very pedagogical way when it comes to the technical aspect of adaptive parameters.

Partitions virtuelles, R elative Values & Absolute Values

Let us first establish the term virtual partition. Manoury’s (1997) conception comes originally from discussions with the late Pierre Boulez, although it was Manoury that expanded on the concept and extended it through Compositions such as “En écho” (1993-1994), “Neptune” (1991), and “Jupiter” (1987).

Virtual partition is a concept that refers directly to the idea of notation as it is used with traditional acoustic music. If we think of Beethoven’s piano sonatas, the notation tells us which notes to play (ie. C4 followed by E4, etc). It might also contain some tempo marks, dynamic markings and phrasing. Do these parameters form the complete list of parameters that a musician can play? The simple answer is no. These are only basic, and often parameters of relative value. A fortissimo symbol does not mean “play at 90 dB”, the symbol is relative compared to what has come before and what will come after. The absolute parameter that we have in this case, is the notes that are written in the sheet music. An A4 will remain an A4. This duality of seeing absolute against relative is also what has given us the world of interpretation. Paul Lewis will not play the same piece in the exact same way as András Schiff even though they will be playing the exact same notes. This is a vital part of the richness of the classical repertoire: its interpretation.

As Manoury points out, in early electroacoustic music this possibility of interpretation was not possible. The so-called “tyranny of tape” made it rather difficult to have more relative values, and in fact also limited the relative values of the live musicians as their tempo and dynamics had to take into consideration a medium that could not be changed then and there. This aspect of the integration of the electronics is a large field into itself which interests this author very much. Although an exhaustive discussion of this is far beyond the scope of this article, it should be noted that adaptive parameters can be used with most of these integration techniques. However, at this point this author does believe that score following and its real-time relative techniques permit this level of interactivity on a higher plane than say the scene system such as in the piece “Lichtbogen” (1986-1987) by Kaija Saariaho where the electronics are set at specific levels until the next scene starts.

Therefore, the main idea of the virtual partition is to bring interpretation into the use of electronics within mixed music. The first aspect to be able to do so is to work with both relative and absolute variables. How does this relate to adaptive parameters? By using electronics that have several relative values that are influenced either by the electronics themselves, the musician(s) or a combination of both, it becomes possible to bring interpretation to the world of electronics. In other words, the use of adaptive parameters within mixed music can bring more interpretation and fluidity into the genre.

Time & Musical Time

The traditional complaint and/or reason for not implementing adaptive parameters/virtual partitions in mixed music has been its difficulty. The Cross-adaptive synthesis project has proven that complex and beautiful results can be made with adaptive parameters. The flexibility of the electronics can only make the rapport between the musicians and computer a more positive one. Another reason that has often been cited is if the relationships would be clear to the listener. This author feels that this criticism is slightly oblique. The use of adaptive parameters may not always be heard by the audience, but it does influence how much the performer(s) feel connected to the electronics. It is also the basis of being able to create an electronic interpretation. Composers like Philippe Manoury for example, believe that the use of a real-time system with adaptive parameters is the only way to preserve the expressivity while working between electronic and acoustic instruments (Ramstrum, 2006).

Another problem that has often come up when it comes to written music, is how to combine the precise activity of contemporary writing with a computer? Back in the 80’s composers like Philippe Manoury often had to use the help of programmers such as Miller Puckette to come up with novel ideas (which in their case would later lead to the development of MaxMSP and Pure Data). However, the arrival of more stable score followers and recognizers (a distinction brought to the light in Manoury, 1997, p.75-78) has made it possible to think of electronics within musical time (ex. quarter note) instead of absolute time (ex. milliseconds). This also allows a composer to further integrate the interpretation of the electronics directly into the language of the score. One could understand this as the computer being able to translate information from a musical language to a binary language.

To give a simple example, we can assume that the electronic process we are controlling is a playback file on a computer. In the score of our imaginary piece, in 5 measures the solo musician must go from fortissimo to pianissimo and eventually fading out niente (meaning gradually fading to silence). As this is happening, the composer would like the pitch of the playback file to rise, as the amplitude of the musician goes down. In absolute time, one would have to program the number of milliseconds each measure should take and hope that the musician and computer would be in sync. However, by using relative time it is easier, as one can tell the computer that the musician will be playing 5 measures. If we combine this with adaptive parameters, we can directly (or indirectly, if preferred) connect the amplitude of the musician to the pitch of the playback for those 5 measures. This idea, which seemed to be most probably a dream for composers in the 80’s has now become reality  because of programs like Antescofo (described in Cont, 2008) as well as the concept of adaptive parameters which is becoming more commonplace.

The use of microphones and/or other sensors allows us to extract more information from the musician(s) and one can connect these to specific parameters however directly or indirectly one wishes. Øyvind Brandtsegg’s software also allows the extraction of many features of sound(s) and map these to audio processing parameters. In combination with a score follower or other integration methods, this can be an incredibly powerful tool to organize a composition.

Examples from the mixed music repertoire should also be named to give inspiration but also show that it is in fact possible, and already in use. Philippe Manoury has for example used parameters of the live musician(s) to calculate synthesis in many pieces ranging from “Pluton” (1988) to his string quartet “Tensio” (2010). In both pieces, several parameters (such as pitch) are used to create Markov chains and to control synthesis parameters.

Let us look a bit deeper into Manoury’s masterpiece “Jupiter” (1987). Although this piece is an early example of the advanced use of electronics with a computer, the use of adaptive parameters was used actively. For a detailed analysis and explanation of the composition, refer to May (2006). In sections VI and XII the flutist’s playing influences the change of timbre over time. The attack of the flutist’s notes (called note-incipits in May, 2006) control the frequency of the 28 oscillators of the chapo synthesizer – a type of additive synthesis with spectral envelope (Ibid, p. 149) – and its filters. The score also shows these changes in timbre (and pitch) throughout the score (Manoury, 2008, p.32). This is around the 23:06 mark in the recording done my Elizabeth McNutt (2001).

Several other sections’ temporality is also influenced by the performer. For example, in section II, the computer will record short instances of the performer which only be used later in section V and IX in which these excerpts are interpolated and then morphed into tam-tam hits or piano. As May (2006) notes, the flutist’s line directly affects the shape, speed and direction of the interpolations marking a clear relationship between both parts. The sections in which the performer is recorded is clearly marked in the score. In several of the interpolation sections, the electronics take the lead and the performer is told to wait for certain musical elements. The score is also clear about how the interpolations are played and how they are directly related to the performer’s actions.

The composer Hans Tutschku has also used this idea in his series “Still Air” which currently features three compositions (2013, 2014, 2014). In all the pieces, the musicians are to play along to an iPad which might be easier than installing MaxMSP, a soundcard and external microphone for many musicians. The iPad’s built in microphone is used to measure the musicians’ amplitude which varies the amplitude and pitch of the playback files. The exact relationship between the musician and electronics vary throughout the composition. This means that the way the amplitude of the signal modifies the pitch and loudness of the playback part will vary depending on the current event number which are shown in the score (Tutschku, personal communication, October 10, 2017). This use of adaptive parameters is simple and still permits the composer to have a large influence between performer and computer.

A third and final example is “Mahler in Transgress” (2002-2003) by Flo Menezes, especially its restoration done in 2007 by Andre Perrotta which uses Kyma (Perrotta, personal communication, October 6, 2017). Parameters from both pianists are used to control several aspects of the electronics. For example, the sound of one piano could filter the other, or one’s amplitude could affect the spectral profile of the other. Throughout the duration of the composition, the electronics are mainly processing both pianos, as they influence their timbre between each other. This creates a clear relationship between what both performers are playing and the electronics that the audience can hear.

These are only three examples that this author believes shows many different possibilities for the use of adaptive parameters in through-composed music. It is by no means meant to be an exhaustive list, but only as a start to have a common language and understanding on adaptive parameters in mixed music.

A Composition Must Be Like the World or… ?

Gustav Mahler’s (perhaps apocryphal) citation “A symphony must be like the world. It must contain everything” is often popular with composition students. However, this author’s understanding of composition especially in the field of mixed music has led him to believe that a composition should be a world on its own. Its rules should be guided by the poetical meaning of the composition. The rules and ideas that will suit one composition’s electronics and structures, will not necessarily suit another composition. Each composition (its whole of the score and the computer program/electronics) forms its own world.

With this article, this author does not wish to delve into a debate over aesthetics. However, these concepts and possibilities tend to go towards music done in real-time. For years, it was thought that the possibilities of live electronics were limited, but in recent years this has not been the case. The field is still ripe with the possibilities of experimentation within the world of through-composed music.

At this point in time, this author is also experimenting directly with the concept of cross-adaptive synthesis written into through-composed music. I see no reasons as to why it shouldn’t be used both in and out of freely improvised music. We should think of technology and its concepts not within aesthetic boundaries, but as how we can use it for our own purposes.

Bibliography

Cont, A. (2008). “ANTESCOFO: Anticipatory synchronization and control of interactive parameters in computer music.” in Proceedings of international computer music conference (ICMC). Belfast, August 2008.

Frengel, M. (2010). A Multidimensional Approach to Relationships between Live and Non-live Sound Sources in Mixed Works. Organised Sound , 15 (2), 96–106. https://doi.org/10.1017/S1355771810000087

Manoury, P. (1997). Les partitions virtuelles in « La note et le son: Écits et entretiens 1981-1998 » . Paris, France: L’Harmattan.

Manoury, P. (1998). Jupiter (score, originally 1987, revised in 1992, 2008). Italy: Universal Music MGB Publishing.

Mcnutt, Elizabeth (2001). Pipewrench: flute & computer (Music recording). Emf Media.

May, Andre (2006). Philippe Manoury’s Jupiter. In Simoni, Mary (Ed.), in Analytical methods of electroacoustic music (pp. 145-186). New York, USA : Routledge Press.

Ramstrum, Momilani (2006). Philippe Manoury’s opera K…. In Simoni, Mary (Ed.), in Analytical methods of electroacoustic music (pp. 239-274). New York, USA : Routledge Press.

Since the crossadaptive project involves designing relationsips between performative actions and sonic responses, it is also about instrument design in a wide definition of the term. Some of these relationships can be seen as direct extensions to traditional instrument features, like the relationship between energy input and the resulting sonic output. We can call this the mapping between input and output of the instrument. Some other relationships are more more complex, and involves how the actions of one performer affect the processing of another. That relationship can be viewed as an action of one performer changing the mapping between input and output of another instrument. Maybe another instrument is not the correct term to use, since we can view all of this as one combined super-instrument. The situation quickly becomes complex. Let’s take as step back and contemplate for a bit on some of the separate aspects of a musical instrument and what constitutes its “moving parts”.

Playing on the sound

One thing that has always inspired me with electric and electronic instruments is how the sound of the instrument can be tweaked and transformed. I know I have many fellow performers with me in saying that changing the sound of the instrument completely changes what you can and will play. This is of course true also with acoustic instrument, but it is even more clear when you can keep the physical interface identical but change the sonic outcome drastically. The comparision becomes more clear, since the performative actions, the physical interaction with the instrument does not need to change significantly. Still, when the sound of the instrument changes, even the physical gestures to produce it changes and so also what you will play.  There is a connection and an identification between performer and sound, the current sound of the instrument. This als oextends to the amplification system and to the room where the sound comes out. Performers who has a lot of experience playing on big PA systems know the difference between “just” playing your instrument and playing the instrument through the sound system and in the room.

Automation in instruments

In this context, I have also mused on the subject of how much an instrument ‘does for you’. I mean, automatically, for example “smart” computer instruments that will give back (in some sense) more than you put in. Also, in terms of “creative” packages like Garageband and also much of what comes with programs like Ableton Live, where we can shuffle around templates of stuff made by others, like Photoshop beautifying filters for music. This description is not intended to paint a bleak picture of the future of creativity, but indeed is something to be aware of. In the context of our current discussion it is relevant because of the relation between input and output of the instrument; Garageband and Live, as instruments, will transform your input significantly according to their affordances. The concept is not necessarily limited to computer instruments either, as all instruments add ‘something’ that the performer could not have done by himself (without the external instrument). Also, as an example many are familiar with: playing through a delay effect: Creating beautiful rhythmic textures out of a simple input, where there may be a fine line between the moment you are playing the instrument , and all of a sudden the instrument is playing you , and all you can do is try to keep up. The devil, as they say, is in the delays!

Flow and groove

There is also a common concept among musicians, when the music flows so easily as if the instrument is playing itself. Being in the groove, in flow,  transcendent, totally in the moment, or other descriptions may apply.  One might argue that this phenomenon is also result of training, muscle memory, gut reaction, instinct. These are in some ways automatic processes. Any fast human reaction relies in some aspect on a learned response, processing a truly unexpected event takes several hundred milliseconds. Even if it is not automated to the same degree as a delay effect, we can say that there is not a clean division between automated and conteplated responses. We could probably delve deep into physchology to investigate this matter in detail, but for our current purposes it is sufficient to say automation is there to some degree at this level of human performance as well as in the instrument itself.

Another aspect of automation (if we in automation can include external events that triggers actions that would not have happened otherwise), or of “falling into the beat” is the synchronizing action when playing in rhythm with another performer. This has some aspects of similarity to the situation when “being played” by the delay effect. The delay processor has even more of a “chasing” effect since it will always continue, responding to every new event, non stop. Playing with another performer does not have that self continuing perpetual motion, but in some cases, the resulting groove might have.

Adaptive, in what way?

So when performing in a crossadaptive situation, what attitude could or should we attain towards the instrument and the processes therein? Should the musicians just focus on the acoustic sound, and play together more or less as usual, letting the processing unfold in its own right? From a traditionally trained performer perspective, one could expect the processing to adapt to the music that is happening, adjusting itself to create something that “works”. However, this is not the only way it could work, and perhaps not the mode that will produce the most interesting results. Another approach is to listen closely to what comes out of the processing. Perhaps to the degree that we disregard the direct sound of the (acoustic) instrument, and just focus on how the processing responds to the different performative gestures. In this mode, the performer would continually adjust to the combined system of acoustic instrument , processing , interaction with the other musician, signal interaction between the two instruments, also including any contribution from the amplification system and the ambience (e.g. playing on headphones or on a P.A). This is hard for many performers, because the complete instrument system is bigger, has more complex interactions, and sometimes has a delay from an action occurs to the system responds (might be a musical and desirable delay, or a technical artifact), plainly a larger distance to all the “moving parts” of the machinery that enables the transformation of a musical intent to a sounding result. In short, we could describe it as having a lower control intimacy . There is also of course a question of the willingness of the performer to set himself in a position where all these extra factors are allowed to count, as it will naturally render most of us in a position where we again are amateurs, not knowing how the instrument works. For many performers this is not immediately attractive. Then again, it is an opportunity to find something new and to be forced to abandon regular habits.

One aspect that I haven’t seen discussed so much is the instrumental scope of the performer. As described above, the performer may choose to focus on the acoustic and physical device that was traditionally called the instrument, and operate this with proficiency to create coherent musical statements. On the other hand, the performer may take into account the whole system (where does that end?, is it even contained in the room in which we perform the music?) of sound generation and transformation. Many expressive options and possibilities lies within the larger system, and the position of the listener/audience also oftentimes lies somewhere in the bigger space of this combined system. These reflections of course apply just as much to any performance on a PA system, or in a recording studio, but I’d venture to say they are crystallized even more clearly in the context of the crossadaptive performance.

Intellectualize the mapping?

To what degree should the performers know and care about the details of the crossadaptive modulation mappings? Would it make sense to explore the system without knowing the mapping? Just play. It is an attractive approach for many, as any musical performance situation in any case is complex with many unknown factors, so why not just throw in these ones too? This can of course be done, and some of our experiments in San Diego has been following this line of investigation (me and Kyle played this way with complex mappings, and the Studio A session between Steven an Kyle leaned towards this approach). The rationale for doing so is that with complex crossadaptive mappings, the intellectual load of just remembering all connections can override any impulsive musical incentive. Now, after doing this on some occasions, I begin to see that as a general method perhaps this is not the best way to do it. The system’s response to a performative action is in many cases so complex and relates to so many variables, that it is very hard to figure out “just by playing”. Some sort of training, or explorative process to familiarize the performer with the new expressive dimensions is needed in most cases. With complex mappings, this will be a time consuming process. Just listing and intellectualizing the mappings does not work for making them available as expressive dimensions during performance. This may be blindingly obvious after the fact, but it is indeed a point worth mentioning. Familiarization with the expressive potential takes time, and is necessary in order to exploit it. We’ve seen some very clear pedagogical approaches in some of the Trondheim sessions , and these take on the challenge of getting to know the full instrument in a step by step manner. We’ve also seen some very fruitful explorative approaches to performance in some of the Oslo sessions . Similarly, when Miller Puckette in our sessions in San Diego chooses to listen mainly to the processing (not to the direct sound of his instrument, and not to the direct sound of his fellow musician’s instrument, but to the combined result), he actively explores the farthest reaches of the space constituted by the instrumental system as a whole. Miller’s approach can work even if all the separate dimensions has not been charted and familiarized separately, basically because he focus almost exclusively on those aspects of the combined system output. As often happens in conversations with Miller, he captures the complexity and the essence of the situation in clear statements:

“The key ingredients of phrasing is time and effort.”

What about the analytical listener?

In our current project we don’t include any proper research on how this music is experienced by a listener. Still, we as performers and designers/composers are also experiencing the music as listeners, and we cannot avoid wondering how (or if) these new dimensions of expression affects the perception of the music “from the outside”. The different presentations and workshops of the project affords opportunities to hear how outside listeners perceive it.  One recent and interesting such opportunity came when I was asked to present something for Katharina Rosenbergers Composition Analysis class at UCSD. The group comprised of graduate composition students, critical and highly reflective listeners, and in the context of this class especially aimed their listening towards analysis.  W hat is in there ? How does it work musically?  What is this composition? Where is the composing? In the discussions with this class, I got to ask them if they perceived it as important for the listener to know and understand the crossadaptive modulation mappings. Do they need to learn the intricacies of the interaction and the processing in the same pedagogical manner? The output from this class was quite clear on the subject:

I t is the things they make the performers do that is important

In one way, we could understand it as a modernist stance that if it is in there, it will be heard and thus it matters. We could also understand it to mean that the changes in the interaction, the thing that performers will do differently in this setting is what is the most interesting. When we hear surprise (in the performer), and a subsequent change of direction, we can follow that musically without knowing about the exact details that led to the surprise.