My first exploration with Experiments in Musical Intelligence involved coding the rules of basic part-writing as I understood them, since part writing constitutes one of the primary superstructures of traditional tonal music. After much trial and error, my program produced a kind of vanilla music which basically adhered to these rules. While basically correct in terms of how the voices move one to another and still conform to classical triadic harmony, the music seemed, at least to the educated ear, lifeless and without much musical energy.
While some of the music composed using this approach did prove fairly successful, most of its output was equally uninteresting and unsatisfying. Having an intermediary - myself - form abstract sets of rules for composition seemed artificial and unnecessarily premeditative. As well, having to code new sets of rules for each new style encountered proved daunting. I therefore revised the program to create new output from music stored in a database. My idea was that every work of music contains a set of instructions for creating different but highly related replications of itself. These instructions, interpreted correctly, can lead to interesting discoveries about musical structure as well as, hopefully, create new instances of stylistically-faithful music.
My rationale for discovering such instructions was based, in part, on the concept of recombinancy. Recombinancy can be defined simply as a method for producing new music by recombining extant music into new logical successions. I describe this process in detail in my book Experiments in Musical Intelligence (1996). I argue there that recombinancy appears everywhere as a natural evolutionary and creative process. All the great books in the English language, for example, are constructed from recombinations of the twenty-six letters of the alphabet. Similarly, most of the great works of Western art music exist as recombinations of the twelve pitches of the equal-tempered scale and their octave equivalents. The secret lies not in the invention of new letters or notes but in the subtlety and elegance of their recombination.
Of course, simply breaking a musical work into smaller parts and randomly combining them into new orders almost certainly produces gibberish. Effective recombination requires extensive musical analysis and very careful recombination to be effective at even an elemental level no less the highly musical level of which I dreamed. For more details on how this process works, please see my three books on the subject from A-R Editions Computers and Musical Style, Experiments in Musical Intelligence, and The Algorithmic Composer and one from MIT Press Virtual Music..
(1) deconstuction (analyze and separate into parts)
(2) signatures (commonality - retain that which signifies style)
(3) compatibility (recombinancy - recombine into new works)
Since the early days of Experiments in Musical Intelligence, many audiences have heard its output in the styles of classical composers. The works have delighted, angered, provoked, and terrified those who have heard them. I do not believe that the composers and audiences of the future will have the same reactions. Ultimately, the computer is just a tool with which we extend our minds. The music our algorithms compose are just as much ours as the music created by the greatest of our personal human inspirations.
For a complete bibliography of books and articles, CDs, and so on about Experiments in Musical Intelligence, click here.