Tape made in Royal College of Music Electronic Music Studio, 1970.
A composer, conductor and performer, to real time electro-acoustic music ; Lawrence Casserley was also professor of electro-acoustic music at the Royal College of Music in London.

By early 1970 the studio had acquired some interesting new equipment, some specially built voltage-controlled oscillators (based on Robert Moog’s published designs), and another EMS product, the Dynamic Filter. This was a very flexible voltage-controlled filter, consisting, in fact, of two filters that could be linked either in series or parallel as well as being used in high pass or low pass mode. This enabled both band pass and band reject filters to be created, with separate voltage-control of bandwidth and band centre frequency (this instrument has also been donated to The Hague collection). I was soon experimenting with networks (remember that word for later) of oscillators and filter to create a variety of sounds. I was particularly interested in the roughly voice-like sounds that could be produced, and one of these experimental patches produced the source material for "Transformations I". The linking notion behind all of the Transformations series was that they present a source sound in direct juxtaposition with transformations of itself. In other pieces the source sound is the live instrument (piano or flute); here it is a continuous take from one of my oscillator/filter networks.
I devised a structure which alternates sections of the original sound with sections of transformation; in each case I used the removed section as material for the transformations, although in some later sections I also used previous transformation sections as material. Each transformation section occupies the same amount of time as the removed section of original sound. It is as though the source sound is travelling behind a window with alternating panes of clear glass and distorting glass. The main component of transformation is a sequence of progressive ring modulation, which is a development of the technique I used in The Final Desolation of Solitude (my first electronic tape piece). The transformations increase in intensity and complexity up to the climactic seventh, before sinking to a quiet conclusion, although once again the apparent innocence of the opening sounds is not achievable; another journey of transformation. As so often in my pieces, this structure, taken on its own, sounds very rigid and limiting, but actually it provides a framework within which I could set my imagination free. This piece has humour and drama that dance around each other in an unpredictable way; it allowed me to improvise with the material.
Two things were crucial to my experience at this time, and both of them can be traced back to Stockhausen’s “Kontakte” (which I had heard in Chicago in 1963 - a crucial epiphany). One is the sense of working directly with sounds as physical objects which can be manipulated, which I have compared with moulding clay (and Stockhausen’s realisation score for “Kontakte" was an inspiration here); the second is that this approach was freeing me from the pitch-based thinking of the music I had been composing before this. In the next two pieces in the ‘Transformations’ series pitch-based composition is certainly important, but it is primarily a means of achieving sound manipulation ends. The relationship between the sound of the ‘source’ and its transformation was becoming the crucial issue.
So what do I mean by “Transformation”? Each of these pieces has a very different sound world, but each is a stage on one journey. This is a journey to explore how sounds can be transformed, how journeys that start from one place can arrive at some very different and often surprising place. A piano generates a series of new electronic sound worlds (“Transformations II”); a flute produces pitches that are otherwise impossible (“Transformations III”); electronic sounds mutate into new forms; and it is the way these changes happen that is the real music. Whether I am transforming lead into gold, or pumpkins into carriages (or indeed carriages into lead, or gold into pumpkins) is less important; it is the way in which those transformations occur, the relationship between the original and the transformation; that is what this music is all about.