Crystalline Strata



Rainer Bürck             Piano

Martin Bürck             Percussion

Lawrence Casserley             Signal Processing Instrument





1               Crystalline Materials                                    08:50

2               Allotropy                                                         11:59

3               Latent Heat of Fusion                                  16:02

4               Different Kinds of Snow                              22:27

5               Quartzite                                                          06:31

6               Crystalline Synthesis                                   07:33


Total time                                                   73:40



Recorded 26 May, 2007               Zehntscheuer, Münsingen, Schwabia

Mixed and Edited, 2008/9                       Bad Urach, Schwabia

Bledlow Ridge, Chilterns


Special thanks to David Stevens for technical assistance





1. Being, relating to, or composed of crystal or crystals.

2. Resembling crystal, as in transparency or distinctness of structure or outline.



n. pl. strata

1. A horizontal layer of material, especially one of several parallel layers arranged one on top of another.

2. Geology A bed or layer of sedimentary rock having approximately the same composition throughout.

3. Any of the regions of the atmosphere, such as the troposphere, that occur as layers.

4. Biology A layer of tissue: the epithelial stratum.

5. A level of society composed of people with similar social, cultural, or economic status.

6. One of a number of layers, levels, or divisions in an organized system: a complex poem with many strata of meaning.

 (Adapted from

I first met Rainer Bürck in 1993, when he and Robert Ruhle were to play a duo piano concert at The City University, London. Unfortunately a power cut interrupted proceedings, and we all spent the evening in the pub. Later, on another visit to the UK, he came to my home and we talked about possible collaborations. He proposed introducing a third player, cellist/vocalist Roland Graeter, and the result was a short tour in Scotland in February, 1997. This was less than three weeks after I returned from STEIM in Amsterdam, where I had been developing the first version of the Signal Processing Instrument (SPI) and recording the CD “Solar Wind” (Touch TO:35) with Evan Parker. The day before we went to Scotland I recorded “Dividuality” (Maya MCD0101) with Evan and Barry Guy in London, and the day after our return from Scotland we travelled to Connecticut College, USA for a Symposium on Interactive Music, where I discussed the SPI and the trio performed again. So Rainer was in at the very birth of the SPI; and our musical relationship has continued ever since.


Several years later I performed with Rainer and his brother Martin in Kirchheim unter Teck during one of my European tours. The performance went well, but the recording was unsatisfactory, so it was not until another tour in May 2007 that we were able to have a serious recording session in the lovely hall in the historic Zehntscheuer (tithe barn) in Münsingen, in the Schwabian Alps. That tour has been very productive; the CDs “Room 2 Room” with Jeffrey Morgan (Konnex KCD5213), and “Integument” with Adam Linson (psi 09.03) have already been released. To me, one of the joys of these three records is how very different they are, which reflects the very different players involved. I was not imposing my style on them, but responding creatively to the different challenges they offered, as they were responding to mine.


Rainer was trained in the contemporary classical tradition, and has played many of the great piano classics of the middle and late 20th century, by Stockhausen, Boulez, etc. He is also a composer and computer programmer, and has developed many of his own sound processing programs. His music can be heard on “Without Fear” (earsay 99001). When improvising, his playing is informed by all this experience and has a classical sense of architecture. This sense is a major force in these recordings.


Martin is a visual artist, as well as a musician who has made some of his own instruments, and has collected many interesting objects which make sounds. He is constantly exploring the hidden internal sounds of his materials. For a recent theatre project he created a fascinating score from the scrap metal of a factory. Other projects include designing sound nights, concerts inside caves, a radio play, sound installations and interdisciplinary art projects. These sensitivities are evident in the way he plays, and make a strong presence in our collaboration.


The two brothers have worked together many times, and their trio ‘Trionys’ with violinist Günter Marx can be heard on “Vector Alpha” (earsay 02001). The fusion of their different sensibilities is the heart of these recordings. I was drawn into the intensity of their collaboration, their continuing conversation, their deep understanding of each other. I found ways to explore and comment on their special world, to enhance and sometimes disturb it, and to add my own intensity to theirs.


Their close dialogue is most apparent in “Latent Heat of Fusion”, where I play a more secondary role, as a sort of cheerleader, commentator and supporter of their collaboration. In “Different Kinds of Snow” the relationships are more fluid, the emphasis shifting constantly between different duos and solos with the others’ backing.


The earlier tracks set out our palette: in “Crystalline Materials” our individual sounds are like snowflakes, which occasionally amalgamate into larger forms (snowballs?), while in “Allotropy”, after my opening dialogue with Rainer, I play increasingly a more leading role, drawing the brothers’ sounds into ever greater drifts of richly layered textures. Towards the end their sounds seem to be swallowed up by the surrounding clouds.


The most complete integration of the trio occurs in the last two pieces, “Quartzite” and “Crystalline Synthesis”, which finally draw together the elements exposed from the beginning; in the final seconds the snowflakes become an avalanche.


Another key element in these pieces is the constant layering of different elements and sonic objects. It might be compared to the “laminar” music of groups like AMM, if our approach to sonic structure was not so different. We are playing constantly with different levels of integration and separation between the layers. This is particularly apparent in my role, partly because my instrument can be seen as a “layer making machine”, but also because of the way I switch between processing Rainer’s sounds, Martin’s sounds and both together. It is as if I am controlling a fountain that springs from two different sources; sometimes I am highlighting differences between them, sometimes fusing their two sounds into one stream; sometimes even both at once. Thus much of the layering springs directly from my transformations.


The brothers’ crisp percussive sounds are marvellously crystalline structures in themselves, and frequently they build these separate sounds into larger crystalline forms, both individually and in duet. Another characteristic of my instrument is that it is a creator of resonances; I have a large array of different resonances and combinations of resonances available, and I employ them frequently to enhance and extend the crystallinity of the sounds, while also multiplying and layering them into “crystalline strata”.


But these are merely the atoms, the building blocks of what we do; it is the architecture that is the music. I have already suggested Rainer’s crucial role in this, but in the end it is the way we interact together, and the way these relationships vary, that creates these forms. And the crux of this is the Signal Processing Instrument, the way it works and the way it influences both my own music-making and theirs.


The origins of the SPI lie in my earliest perceptions of making electronic sound in the late 1960s. One of the things that drew me to electronic music at that time was the perception that I could mould a sound, in a way analogous to moulding clay; by pushing in and pulling out different parts of a sound I could shape it like a sculptor. A sculptor knows that s/he must respect the clay, understand the clay, trust the clay (or the stone, wood or metal), in order to produce the desired results. It was this idea of interacting with the materials that really appealed to me, and this led directly to my long dedication to live processing of sound.


For many years this was a difficult and precarious undertaking. Quite early on I was convinced that developments in digital technology would provide the answer, and from the late 1970s I worked on creating digital processing systems to fulfil my dreams. While I had a few successes, this was mostly a long period of learning about how to interact with sounds in performance. From the early 1990s the tools I was looking for began to become available to me, and, as so often happens, this coincided with changes in my thinking in response to new challenges. Improvisation, which had always been part of my work, was becoming more and more important to me, and it was clear that I needed an instrument that could balance with those of my colleagues.


In particular, I worked on a number of projects with tubist/composer/improviser Melvyn Poore. In one of these I needed to find a satisfactory way of triggering different events in performance, and the logical solution was to take advantage of my percussion background and use the MIDI Drum Pad controllers that were becoming available around that time. This was so successful that I started looking for ways of incorporating them into the instrument. Many musicians working with live sound processing focus on the use of sampling; my own practice stems from a different premise. I have worked for many years with delay structures; in the early days this meant stringing together two or more tape recorders, which was always a tricky business; later it consisted of several digital delay line units, less tricky but harder to control coherently. I liked the idea that I had the whole stream of sound available, and I could choose (within limits) how far back to look for a sound. Also I didn’t want to divert my attention away from playing to recording things; a delay line is always recording. The new technology allowed me to get away from these limitations and rethink my use of delays. It also gave me a better way to give my own gestural input to the music.


In January, 1996 I made the first of several residencies at STEIM in Amsterdam. During that time I worked on two new delay structures. The first was simple in principle, but was completely impossible either with the old analogue systems or commercial muli-effect units. I made a long delay of over twenty seconds, with more than thirty taps at different times, which I could move around; by changing the relationships of the taps I could create very different kinds of musical space around the sounds. The second structure was more radical, a delay line that could be played with my drum pads. Essentially this allows me to find sounds in the delay and play them as a polyphonic instrument. In 1997 I returned to STEIM with Evan Parker, and we worked together on building this into an instrument; our work is documented on the CD “Solar Wind”.


This is not just a technical issue, although there were certainly many technical problems to solve. What happened at that time was that I finally found a way both to manipulate the materials (the clay) as I wanted and to respect them as they deserved. For my clay is not just a neutral substance, but the result of the artistry of my collaborators, so my respect for these sounds is even greater. Over the years since that special collaboration at STEIM I have slowly refined the instrument in response to the experience of playing it with a wide variety of musicians.


My responses to the sounds that come into my instrument are complex and varied; as I said before, it is the interaction with the materials that is what my music is about. It is not so much the actual sounds my instrument makes, but the way they relate to the sounds from which they are derived – the way my manipulation of the clay relates to its original state. But this is a two way process: the way the other performer responds to what I do is just as important. I am not only interacting with a sound but with a performer. I often talk of a relatonship between directedness and acceptance in my work; it is a balance between what I feel is right and what the sounds, and the other musicians, require of me. Of course this is true of any group improvisation, and the views of those musicians are equally important. As Martin Bürck puts it: “I enjoy reacting to Lawrence`s electronical inputs - for instance when he creates sort of sonic clouds out of a single percussion sound and I can react and comment on this with the same or slightly changed original sound. Sometimes his reaction to our material is like opening a window to a new scene using our colours, and we can either slow down or accelerate this new process.”


Adam Linson, in the notes to our duo CD “Integument” says: “I get the feeling that interacting with you, on the model that your approach demands, serves to reveal your performance as that of an autonomous instrumentalist rather than an extension of your sound source.” This was certainly one of the aims of the SPI, to be on some kind of “level playing field” with my colleagues, but I am “extending” the sound source as well; I am taking the sounds on journeys of transformation and re-creation. The degrees of “sameness” and “difference” between what I do and my colleagues do (have done) are vital. For me the musical meaning often is exactly in that space between the two.


Rainer Bürck has commented: “I’d performed contemporary music as a pianist and composed electro-acoustic music of my own before I ever got involved in improvised music, but my first experience playing spontaneous music back in 1995 opened up completely new horizons for me. I’ve collaborated with a lot of different musicians since, but working with Lawrence is always something special. By its very nature collective improvising is about playing off of each other, but making music with Lawrence also means responding to your alter ego. Lawrence always throws your own sound back at you in completely unpredictable ways. The outcome is a complex and exciting situation of mutual interaction that takes you ‘on a sound trip to the outer limits and beyond’ (Press & Journal, Aberdeen, 27. 2. 1997).” That comment was from a review of our trio with Roland Graeter, but the same principle comes into all my collaborations. There seem to be two levels of interaction here: the usual gestures and responses of collaborative improvisation; and another thing that happens when the original gesture is returned in a new version. I might quarrel with the word “unpredictable”, but I know what he means. My responses involve very complex behaviours, both my own and those of the instrument; I am constantly on a cusp between predictability and unpredictability, between order and chaos. The musical meaning lies in the space between these as well.


Linson again: “As the process of mutual interaction unfolds we both reveal something of each other; I find we have opened up a space or a world where we co-exist, which can emerge to other listeners, who can also co-exist there”. Revealing something of each other, I believe, is what makes this collaboration with Rainer and Martin so special. Each of us was taken beyond the usual; we had to find new ways of thinking and feeling about what we do – to find spaces and worlds where we could coexist. If these spaces are sometimes abrasive, awkward or tense that is all part of that journey, and part of the crystallinity.


Martin again: “He can be sort of a mirror for us, inviting us to a dialogue with our own musical material - or sometimes he might kick off the whole process by crossfading with strong stuff. I like to offer him material about which I know it is good for processing, and I might let him hunger for that on the other hand. The awaiting of the processed material can open spaces of ‘unplayed’ time and thus create a very special way of musical development - more open, more listening: my own sounds and Lawrence`s processed comments to that are like two answers at the same time but in different languages.”


As Rainer puts it: “What we are trying to do is to create a coherent musical entity – a spontaneous composition in real-time. The live electronics mediate the distinct sound worlds of the acoustic instruments while simultaneously transforming them into something completely different and new.”  I think that puts the emphasis too much on what I am doing; the responses of Rainer and Martin are just as important in finding those spaces and worlds where we can coexist; the journey of transformation must be undertaken together.


Adam Linson once more: “There is a pronounced difference presented by the technology and technique you have developed over the years. During our sessions, through the music, you were always revealing some (even to me) hidden aspect of what I was doing, using me as a source but never reducing me to a mere resource.” It is my reverence for the sound, my respect for the “clay”, that started all those years ago, that is the fundament of these collaborations. “Source” is a word evoking power, energy, life, creation. Without that force from my collaborators (the “source”) my art would never happen the way it does. I love the challenges thrown up by that simple fact.


In May, 2007, within a space of two weeks, I worked with some very different collaborators and produced some very different music. These recordings are the very essence of what I do, and without these wonderful collaborators I could not have achieved this. I am honoured to number Rainer and Martin among them.


Lawrence Casserley

May, 2009