Mycomposition is marked by a tension between free and formal elements. In my early work I sought to marry abstract formal structures , eg canons and proportional structures, with dramatic shapes, often setting the two elements in direct contrast, or using them to articulate different aspects of the work. From 1969 my work in electronic music led me to introduce the concept of transformation into my work. The series of works entitled "Transformations" embody this principle. I studied composition at the Chicago Musical College and at the Royal College of Music, London, continuing at the RCM to study electronic music with Tristram Cary.
My early work in Chicago includes a set of "Orchestral Studies" based on ideas taken from visual art and literature, a set of short piano pieces and the chamber ensemble work "7 Pieces for 14 Players". Although influences of Schönberg and Webern are obvious, I never adopted a strict 12-tone technique, prefering to use my own interpretation of hexachordal and tetrachordal structures. The most rigorous use of this approach is found in the organ work "Exultation for the Expulsion from Eden", an idea based on the closing section of Milton's 'Paradise Lost'. Other early influences include Varése, most notably in the "Orchestral Studies" and "7 Pieces".
My first electronic work dates from 1969. "The Final Desolation of Solitude", the title from a quotation from T.S. Eliot's 'The Cocktail Party', was made in the new RCM studio, using simple oscillators and a progressive transformation technique using ring modulation that was to become a hall-mark. Since that time the use of electroacoustic means has dominated my work.
The first live electronic work also dates from 1969. "Solos, Commentaries and Integrations", for Clarinet with live processing, percussion and tape takes the form of an abstract drama with the clarinet as protagonist, the tape as antagonist and the percussion as 'chorus'. There is also an underlying formal structure based on rhythmic canons which generates the percussion and clarinet music as well as the proportions of the sections.
In 1970 the first two works in the 'Transformations' series appear. The tape work "Transformations I" utilises another proportional outline underlying a dramatic idea, and is another example of progressive transformation technique. The unifying idea of the series is of presenting a source sound in direct juxtaposition with transformations of itself. The next two works in the series are live pieces, with the source sound being, respectively, piano and flute. The final work is an extended tape setting of a group of poems by my father, J.V. Langmead Casserley.
Another key line of work at this time stems from a commission for a mass setting for Pentecost, "Missa Spiriti Sancti". This led to a series of works entitled "Kyries and Alleluias" and represented another strand of ideas about drama and ritual. This leads to the massive "Kyries and Alleluias IV", which was never performed. It was intended that the two strands become combined in the whole evening work "Eclipse", combining it with "Transformations IV" and a projected live computer piece "Aura". But most of the work of the 70s was focused on the multi-media group 'Hydra'.
During that time, as well as exploring relationships with other media and the increasing use of improvisation, I developed ideas about the use of live electronics and the potential of computers in performance. A key work at the beginning of the 80s was "Angel Music" for oboe, amplified percussion and live electronics, part of which was performed in 1981. Whereas in the 70s I was stretching the available resources to the limits of the possible, now I found the artistic ideas outstripping the available possibilities, so "Angel Music" remained incomplete.
Much of the 80s was spent seeking ways to put my ideas about live computer processing into practise. I was also involved in setting up the Nettlefold Festival and the Electroacoustic Cabaret. Consequently there are fewer significant works from this period, and these are exclusively for the Cabaret and related activities.
In 1991, I was invited to prepare a work for performance at the RCM in celebration of my 50th birthday. As most of my current work was so closely involved with specific groups as to be unsuitable, I turned to a long-held desire to form "Missa Spiriti Sancti" into another kind of concert work. The result was "Ritual Dances" for ensemble and live electronics, my first purely concert work since "Vista Clara" in 1982.
In 1992 came a significant technical turning point with the appearance of the IRCAM Signal Processing Workstation. At last something close to my dreams of a computer performance system was available. As well as re-realising some works of the 80s to complete their original intentions (eg "PanHarmonic" and "The Monk's Prayer") I have composed "UbAtAbU" for tubist Melvyn Poore and "The Garden of Forking Paths" for guitarist Richard Durrant. "UbAtAbU" is a 90s version of the 'Transformations' theme, utilising a complex web of computer processes. "The Garden of Forking Paths" is the culmination of a strand, including "The Unending Rose" and "Labyrinth" which has been influenced by the work of Jorge Luis Borges.
The 90s have also been marked by a further increase in my work in improvisation, particularly the development of a Signal Processing Instrument for improvisation based on the ISPW.