Processes as a Space Outlined by the Vertical and Horizontal

These descriptions of electroacoustic processes, implemented in the current incarnation of the piano+, indicate the possibilities of working with the vertical and horizontal axes of the spectrum. This conceptual abstraction can be pushed further: each process has its strengths or focus within a particular area that can be placed within an imaginary space. It is not considered important here how the qualities of the processes are aligned to the directions in the space, however, as an example Figure 4.13 shows an amended version of the abstraction of sound properties (see Figure 2.1).

385 _{Performed at Goldsmiths 29.06.2005. Audio Recording included on Data-DVD file name:}

Study_III_(shifting_focus).mp3

386 _{Solo performance at University of East Anglia, Music Department, on the 10.10.2005.} 387 _{Resonators~ is available for Max/MSP from CNMAT (http://cnmat.berkeley.edu/patch/4019).}

timbre placement, locality time filter, ring-modulation, transpositions amplification, panning, diffusion, ambisonic delays, sampling

Figure 4.13: Abstraction of sound properties amended by a selection of suitable electroacoustic processes

When considering the qualities of the processes as parts, areas, poles, junks – part of the consistency – of the space, we can imagine that the parameters of the effects translate into a imaginary location, not necessarily as a coordinate, but as a descriptor. Parameter changes can then be considered as movement into a different part of the space whether this results from the modulation of the sound by a single process or a mixture of several serial or parallel effect processes.

For the performance activity itself, the technicalities of positioning the parameters of the sound ought to be irrelevant. Their control ought to be convenient without disturbing the musical flow. An awareness of the potential to relate to every sound within an imaginary parameter space will assist decision processes. To find the musically appropriate place one has the flexibility to move slightly more into one direction to enhance the processes on the vertical, i.e. to decrease the spectral density of the sound texture, then maybe to adapt the horizontal, so that textures are prolonged or repeated in order to move further away from the acoustic quality of the piano.

The described stage of the development the piano+ was considered sufficiently flexible, and most importantly, showing contingent but influenceable qualities, so that further developments could be put on hold. Although in the period from 2004 to 2006 several other technical paths were explored and considered388_{, some of which are briefly} mentioned at relevant places within this thesis, they will not discussed in technical

388 _{E.g. colour-mediated parameter space, video control by colour tracking and gesture recognition using}

MnM (IRCAM), and algorithms such as Ollie Bown’s CTRNN (Bown 2006), boids (http://

www.red3d.com/cwr/boids/), CataRT by Diemo Schwarz (Schwarz 2006), the now discontinued multi- layer perceptron (MLP) by the CNMAT (http://archive.cnmat.berkeley.edu/MAX/neural-net.html) (all links were last accessed 21.07.2012).

detail. The development was ‘frozen‘ under practical considerations as well as some approaches would conflict with the aesthetic of the proposed performance practice. It is thought to be a crucial aspect to consciously allow a prolonged period of practical exploration and application of its instrumental properties within the musical practice described in Chapter 3. Part of this decision has also been to limit the audio processes to a fixed selection. It became evident that the approach to develop an extended instrument requires time to learn the instrument. It is important to develop an understanding of its potential and to engage – as with the piano and the acoustic extended techniques – with the role the electroacoustic processes can play within an improvised performance approach. This decision has facilitated a concern with contingency within the electronics and highlighted the difficulty to induce meaningful musical responses of the system which yield a comparable element of surprise to the performer.

Nevertheless the design of the implemented control structure allows the user to ‘hook up’ the system to data streams supplied by generative approaches, where changes are occurring due to changes within sophisticated algorithms. Joint research and experiments have involved to combine the piano+ with Bown’s CTRNN389_{, a project which was} continued within the LAM research group390_{, and has “offer[ed] an opportunity to} implement [...] contingent relationships between performer and electroacoustic process, generating micro structures that control electroacoustic processes in turn dependent on the performer’s activity.”391 _{The means for parameter mapping were developed using my} colour-mediated parameter spaces developed in Max/MSP/Jitter: After observation of the CTRNN behaviour represented as a movement inside a virtual space in correlation to the vector-based input (usually a combination of two indirect controller streams, e.g. xy-axis of tilt sensor) the user “could draw colour-coded regions into the 3-D space that he or she wishes to correlate to specific parameter settings of an instrument.”392 _{The output of} the colour-space are RGB colour values which are then separately usable as indirect controller streams, e.g. the value of the colour red could control the strength of ring- modulation etc.. The defined goal to find a solution never reached the stage that the

389 _{Bown and Lexer 2006.}

390 _{Prévost’s performance in Cafe Oto 2009 using the software of the piano+ system in combination with}

Bown’s CTRNN algorithm. LAM workshop in Summer 2009.

391 _{Bown and Lexer 2006, 6.}

CTRNNs could be trained and evolved in real-time, thus technical realisation of heuristic algorithms were never implemented into this system.

The processes for the recordings of the realisation of Cage’s Electronic Music for Piano393 used completely randomised controls for the parameters. Colour coded star maps were loaded into a 2-D space and a randomised movement retrieved the proximity to the ‘stars’ as colour values being mapped to the parameters.

These activities have proven that the current implementation of the piano+ yields much potential for further extension and research to include behavioural algorithms and machine listening strategies in the future. Within this thesis, however, the research into this field became marginalised, as the goal was set to research the instrumental qualities of the system, rather than developing a musical machine. It remains an important aspect that, despite the research into more flexible control structures and approaches, the processes are seen as empty vessels to be filled by the musical activity. In consequence each decision about process and its control retains direct implications on the musical potential. But it is proposed that these developments have narrowed the gap so that characteristics emerged not unlike the acoustic potential of physical instruments, as the interaction has become more flexible and requires significantly less intervention into the setup of the program (usually by operational tasks) during the performance. Some similarities can be found within the physical world: exchanging the means of sound activation, i.e. replacing the mallet with a bow. My observation how frequent Eddie Prévost manages to get pitches out of the bowed tam-tam which are in harmonic relationship to the pitches played by other players has let me wonder whether physical objects exposed to vibrations more easily be excited on sympathetic resonances within the material. Another example is the , slightly more understandable experience using the feedback through the pickups of the piano+ which build more easily on frequencies of the sympathetic vibrations of the piano strings.