Contributors’ Notes

C D C O M P A N I O N zyxwvutsrqponmlk Contributors’Notes MY COMPUTER-COMPOSEDINSTRUMENTAL WORKS OF THE 1980s Charles Ames, 68 Stevenson Boulevard, Eggertsville, zyxwvu NY 14226,U.S.A. During the 1980s,I produced a series of compositions for live players using programs both to organize the forms and to select the notes. The series included zyxwvutsrq Crystals (1980) for string ensemble, Protocol (1981) and Gradient (1982) for piano, the Eleven Demonstrations for clarinet, Undulant (1983) for seven players, Excursion (1984) and Artifacts (1984) for amplified guitar, Maze (1986) and Concurrence (1986) for violin and Metaplex (1993) for flute. In each case, my concrete objective of producing original works was supplemented by a transcendent purpose: to conduct an introspective investigation of compositional decision-making. Almost all of the pieces listed above were paired with articles documenting what my programs did and whyzyxwvutsrqp [13.The programs were invariably developed from scratch for each new project. Many relied on artificial intelligence search strategies that leavened “black-and-white”constraints with “shades-of-gray”heuristics. My emphasis on live instruments rather than computergenerated sounds in the pieces up to and including Undulant was necessitated by lack of access to sound-synthesis technology .Beginning with Excursion and Artifacts, however, I came to embrace my late mentor Lejaren Hiller’s view of instrumental idioms as resources to be exploited. Where my earlier programs forced the music to conform to instrumental ranges, hand spans, etc., the material for Excursion and Artifacts was activelydriven by guitar idioms [2]. For Excursion, this meant generatinga catalog of chords from which the program could choose. Artifacts took idiom even further by mapping out each note on the fingerboardand making note selection contingent on the program’s ability to derive a plausible fingering . (Since the program’s fingerings were only plausible, not optimal, I refrained from indicating them in the score.) The two guitar pieces also saw the maturation of the method of realizing compositional balances that I call “statisticalfeedback .” There is a synthetic tonality at play in these pieces, wherein passages are characterized by distributions of weights accorded to the chromatic notes. Statistical feedback allowed my programs to realize these distributions in an active way. In effect, it was as if the program were constantly monitoring its own choices and telling itself when to try something new. The performance of Artifacts by Douglas Hensley on the accompanying compact disc is the work’s first published recording . It is also the work‘s first performance by a live player. References zyxwvutsr and Notes 1. These articles were published, for the most part, in InterJare: zyxwvutsrqponm Journal oJNm Music. For an overview of techniqnes, read “QuantifyingMusical Merit,”Inter- zyxwvutsrq jace21, No. zyxwvutsrqpon 1.53-93 (1992). 2. The programs developed to generate Artifacts and its companion Excnnion are described in “Two Pieces for Amplified Guitar,” Inlerface: Journal oJNerv Music 15, No. 1.35-58 (1986). A graph profiling Artifactsappears on page 50. CharlesAmes is a composer and theorist who has been a pioneer o f computer-aided composition and the use o f probability theory in music . Through Itis many pieces and theoretical articles (published in Leonardo, Leonardo MusicJournal, Perspectives of New Music , Interface and Computer MusicJournal), he has made an important contribution to the history o f mathematical and computerbased composition. Ames is the author o f the computer-music language Compose. MICROTONALAND STRUCTURALASPECTS OF MYMONODIES IAND 1 1 Warren Burt, P.O. Box 2154, St. Kilda West, Victoria 3182, Australia. Tuning zyxw M y Monodies I and IZ is a set of two pieces for microtonal guitar that Larry Polansky requested I compose for him. When Polansky asked me to write the compositions, I wondered how I could write a microtonal piece for normal guitar, given the nature of its fretting. It occurred to me that even though the fretting might be fixed, implying that each string would be in 18tone equal temperament, the overall tuning of the instrument need not be. My first thought was that if, for example , each successivestring on the guitar was detuned by 1/ 6 of a semitone further than the string before it, one might end up with a unique...