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## Algorithmic Compositions By Michael Edwards

> "Formerly, when one worked alone, at a given point a decision was made, and one went in one direction rather than another; whereas, in the case of working with another person and with computer facilities, the need to work as though decisions were scarce—as though you had to limit yourself to one idea—is no longer pressing. It’s a change from the influences of scarcity or economy to the influences of abundance and—I’d be willing to say—waste." (John Cage)

For centuries, composers have taken advantage of listeners' ability to build musical-structural relationships in time in order to formalise the compositional process. Formal planning cannot be conflated with algorithmic techniques, but that the former should lead to the latter was a historical inevitability. Algorithmic composition usually involves the use of a finite set of step-by-step procedures, most often encapsulated in software routines, to create music. All the works on this release were created by the author with his algorithmic composition software, "slippery chicken".

The potential for software algorithms to enrich our musical culture has been established, in the 50+ years since such techniques were first introduced, by personalities as diverse as Hiller, Xenakis, Cage, and Eno. There are many riches to be mined in algorithmic composition as, amongst other benefits, the expression of compositional ideas in software often leads to unexpected and surprisingly new, exciting results, and these can seldom be achieved via traditional means. Algorithmic composition techniques can thus play a vital and energising role in the development of modern music across all genres and styles.

An open-source, specialised algorithmic composition programme written in the general programming language Common Lisp and its object-oriented extension, CLOS, "slippery chicken" can be seen as a bridging technology. Traditional composition training in the West does not usually include algorithmic or computer music techniques, despite the fact that many composers use the computer regularly in their work. If the use of algorithmic techniques is to increase, as the author believes is inevitable, it is essential that bridging mechanisms are found. This is true of most new technologies: In industry, a leap from one technology to another presents a business risk, even if the main task is shared, as with the shift from the typewriter to the word processor. Thus we have transition solutions, often with computer software and even hardware that have a rather analogue feel to them. Most word processors, for instance, have a virtual sheet of paper and virtual tab stops. We type with a keyboard that is not by accident related to the typewriter. However, when extended over decades and in different contexts, this approach can become a hindrance. A significant part of the music software industry still offers interfaces and concepts developed from, and in some cases ever more reminiscent of, analogue studio equipment. Nostalgia marketing would often seem to be the motivation behind the interface, rather than the oft-heard argument that analogue processing is superior to digital, ergo an analogue emulation is preferable in the absence of such hardware. Irrespective of the veracity of that argument, the utility of such music software interfaces and their resultant workflow is often questionable; sometimes they are quite simply cumbersome. Systems based around or including programming interfaces are arguably more appropriate; they also offer the potential to move further along the technology bridge.

One such programming interface is "slippery chicken". Work on this software has been ongoing since 2000. By specialised as opposed to generalised, it is meant that the software was originally tailor-made to encapsulate the author’s personal composition techniques and to suit his own compositional needs and goals. As the software has developed however, many general-purpose algorithmic composition tools have been programmed that should be useful to a range of composers. The system does not produce music of any particular aesthetic strain; for example, although not programmed to generate tonal music the system is quite capable of producing it. Furthermore, the software's release as open-source, object-oriented Common Lisp code encourages further development and extensions on the part of the user.

The algorithmic system in "slippery chicken" has been used to create musical structure for pieces since its inception and for several years now has been at the stage where it can generate, in one pass, complete musical scores. It can also, with the same data used to generate those scores, write sound files using samples, or MIDI file realisations of the instrumental score. The project's main aim is to facilitate a melding of electronic and instrumental sound worlds, not just at the sonic but also at the structural level. Hence certain processes common in one medium (for instance sound file slicing and looping) are transferred to another (the slicing up of notated musical phrases and the instigation of sub-phrase loops, for example). Techniques for the innovative combination of rhythmic and pitch data—arguably one of the most difficult aspects of making convincing musical algorithms—are also offered.

Perhaps the developments arising from the debate surrounding the relative merits of analogue versus digital studio technology has most convincingly shown that combining the old with the new is the best solution. This applies just as well to music composition and performance. Formats that continue to include rather than bypass the talented and highly-trained acoustic musicians which our musical infrastructure has at its disposal yield arguably the most impact, particularly when viewed, for better or for worse, from the audience’s perspective. To this end, hybrid works combining digital and acoustic instrumental technologies are ideal. "slippery chicken" is focussed on exactly such musical bridging solutions: using the computer to combine and meld together electronic and acoustic resources at both the structural and formal level.

Michael Edwards, Edinburgh, May 9th 2012