Heliodor Label - HS 25053
manufactured by MGM records

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COMPUTER MUSIC
from the
UNIVERSITY OF ILLINOIS
SIDE ONE
LEJAREN MILLER&emdash;LEONARD ISAACSON
ILLIAC SUITE FOR STRING QUARTET (1957)*

In the last few years electronic digital computers have become familiar in a variety of musical applications. Some uses are straightforward such as the sorting and processing of musicological documents, the development of automated printing of scores and parts. Scholastic applications have also involved the study of style and structure. Computers serve scholars" needs because they- handle masses of data for comparative or statistical evaluation. In addition, computers have provided a major breakthrough in the study of musical timbre&emdash;a field sadly neglected till recently because of inadequate laboratory instruments. This can now be done by analog-to-digital conversion. In other words. sounds&emdash;vocal, instrumental, electronic, etc.&emdash;can be entered into a computer where they are converted into digits. These digits, in turn, can then be subjected to quantitative acoustical analysis. Conversely, the direct generation of sound with computers by "digital-to-analog conversion" is now also quite advanced technically. In this process, wave forms are computed from algebraic expressions and changed into fluctuating voltages impressed upon audio tape.

Nor has the composer neglected the computer. And even though the compositions thus far produced with computers raise more questions than they answer, many composers already regard computers as important new tools of their craft. For example, we now teach a two-semester course for graduate students in music called "Composition with Computers." Moreover, Illinois is far from being the only place where computer composition is taken seriously, for there is similar experimentation in computer methods for composition going on in a number of other locations both in this country and in Europe.

The Illiac Suite for String Quartet of 1957 is the first substantial piece of music produced with a computer. I had been working in the Chemistry Department of the University of Illinois on some problems in statistical mechanics that involved the solution of what we call "restricted random walks." A very crude example of such a walk would arise if I were to walk through a city and flip a coin at each corner to tell me whether to turn left or right. Since it is a cumbersome process to obtain solutions to these problems whenever they are at all subtle or complex, we used ILLIAC I to help out. Since I had also been composing music for years, I observed that if we could program a computer to simulate a "walk" through, say, ordinary space, we could also simulate a "walk" through a grid defined to represent musical elements such as pitch, rhythmic durations, and timbre choices. Leonard Isaacson and I thus assembled enough material to form the Illiac Suite. We organized our results into four movements called Experiments I, 11, III and IV.

Experiment I is a chronicle of "getting started," moving from monody, through two-part writing to four-part writing. We arbitrarily chose some rules of strict counterpoint, an archaic but nevertheless highly codified compositional technique, as the test medium. In Experiment 11, counterpoint rules are progressively introduced as the movement unfolds. In Experiment III we shifted our focus to the 20th century with some chromatic harmony, less rigid rhythmic patterns, modern playing techniques, tone rows, and so forth. Finally, in Experiment IV, we examined a purely mathematical and computer-oriented technique for composition. Experiment IV is an elementary example of "stochastic music," that is to say, music dependent on probability and weighted frequency distributions. Subsequently, Leonard Isaacson and I wrote a full account of our work in a book called Experimental Music, and I believe ILLIAC I was eventually sold as scrap for $67.

About that time I was employed by our School of Music to set up an electronic music studio and it wasn't until 1962 that Robert Baker and I really got started on MUSICOMP and the Computer Cantata. MUSICOMP is an expandable set of programs for composition that is written in SCATRE (an IBM-7094 assembly language) and to a lesser extent in FORTRAN. It consists of three basic groups of routines: (a) System regulatory routines that set up format, data input and output a choice order code, instrument ranges and playing limitations, and other bookkeeping chores. Ultimately, these routines will also provide mnemonics that are more familiar to musicians than most computer terminology. (b) Compositional subroutines, of which some 30 to 40 are now operational. (c) Special output routines that provide data for sound synthesis. Obviously, the compositional subroutines are the heart of the matter because they provide the composer with statements that control the successive selection of notes rhythms, phrases, and so forth. A few of the subroutines we now use include such procedures as generating tone rows, generating chords, generating rhythmic groups, choice of rest or play, and matching like rhythms. These and the other subroutines are derived from both traditional and speculative compositional techniques and can be exploited in both deterministic or probabilistic contexts depending on their user's preferences.

We wrote the Computer Cantata in 1963 to illustrate what we could do with the relatively few subroutines we had at that time. It is organized in the following symmetrical arch form:

1. Prolog to Strophe I; Strophe I.
2. Prolog to Strophe II; Strophe II.
3. Prolog to Strophe III; Strophe III; Epilog to Strophe III.
4. Strophe IV; Epilog to Strophe IV.
5. Strophe V; Epilog to Strophe V.

The five main Strophes are stochastic settings of five successive approximations of spoken English. These texts were generated by Professors Hultzen, Allen, and Miron of the University of Illinois as an, experiment in speech research. The music : is correlated to these texts and goes from a state of great disorder in Strophe I to some degree of order by Strophe V. The Prologs and Epilogs, in contrast to the Strophes themselves, are concerned with rhythmic organization for percussion, l total serialism and scales of 9 to 15 tones per octave realized by a simple sound synthesis scheme devised for the CSX-1 computer. We deliberately left this synthetic sound crude. How it can be refined is exhibited in Herbert Brun's more recent Sonoriferous Loops, also composed at the University of Illinois.

Much nonsense has been written about computers "thinking" and "creating." After all, a computer is really nothing more than a complex array of hardware. It can be tremendously useful hardware, however, but only if you know the limitations of programming logic and how to ask sensible and precisely formulated questions. Recently, the Computer Cantata was broadcast by a radio station and some listeners who missed the announcer's remarks called to ask, "Who wrote that?" The answer should be obvious.

Should a person listen to these two pieces as he might "ordinary music?" Yes I think, but with this important qualification: They are much more didactic than expressive compared to most music. These pieces are truly experimental because they are concerned with revealing process as well as being final product. They are embodiments of objective research results. They are laboratory notebooks. Sometimes the results have surprised us because a compositional routine seems less effective than expected, sometimes more so. If I were to delete everything that disturbs me esthetically, I would falsify the research record. So, for the present, my objective in composing music by means of computer programming is not the immediate realization of an esthetic unity, but the providing and evaluation of techniques whereby this goal can eventually be realized. For this reason, in the long run I have no personal interest in using a computer to generate known styles either as an end in itself or in order to provide an illusion of having achieved a valid musical form by a tricky new way of stating well-known musical truths.

(Notes by Lejaren Hiller)

Lejaren Hiller is presently a Professor of Music and director of the Experimental Music Studio at the University of Illinois. His background includes science as well as music, a point reflected in the fact that his publications include articles, patents and books in scientific fields as well as in music. He has composed some 40 compositions of all sorts, for orchestra, chamber ensembles, theater, TV and films as well as for experimental media. His most recent compositions include Machine Music (recorded on H/HS 25047), A Triptych for Hieronymus (a large dramatic work) and Suite for Two Pianos and Tape.

Leonard Isaacson did his graduate work in physical chemistry at the University of Illinois. He currently works in computer research at the Standard Oil Company of California.

Robert Baker did his doctoral research on a statistical analysis of aspects of classical harmonic style. He is presently teaching composition at Washington University and runs, with Robert Wykes, its electronic music studio.