Between The Idea And Work – Course Of Musical Data Processing

If musical data processing is essential us so much today, it is that it gradually created tools which are radically modifying the manner of thinking the music. However, its history is short. It merges with the development of numerical technologies: computers, initially, accompanied by creation by the languages symbolic intended for the programming, then with a whole troop of inventions in numerical technology. Enough early in its history, data processing will be shown sufficiently ripe to accommodate concerns of all kinds, energy of accountancy to scientific research, while passing naturally by what interests us, artistic creation.

And it is undoubtedly there that it is necessary to distinguish what arises from data processing itself, and what belongs rather to the broader world of numerical technology. The music amply draws from these two fields its new resources. However, since the field of the sound is converted today into audio numerical, the distinction is essential. Musical data processing is born from the meeting of the musical concerns and the environment resulting from numerical technologies and the specificity of the computer, on the one hand, and of the scientific fields which clarify its research topics. If the musical composition appears there in good place, practically all the other activities of the music are found there. And musical research partly covers the ground cleared by data processing, acoustics, the treatment of the signal, even cognitive psychology: thus musical data processing is at the center of several musical, scientific and technical fields.

But it is the recourse to the specific contributions of the data processing which characterizes its step. New conceptual tools are unceasingly provided by the artificial intelligence, which are concretized by languages such as Lisp or Prolog. They are put at once at the musicologist assistance or abstracting service to the composition. Research in systems real time and on the interfaces interactive makes it possible to conceive new connections between the instrumentalist and the electronic universe.

Great stages of musical data processing

With the origin of musical data processing, one finds two types of activities, independent one of the other. If these activities prudent today, it is in another manner that the original vision which caused their birth could enable to foresee. These two types of activities are: the musical composition, and production of the sound. In both cases, the manufacture of the desired result is ensured by the computer. These two types of activities are appreciably contemporary. The first serious tests of musical composition per computer go back to 1956: it is on this date that Lejaren Hiller calculated a partition using rules encodes in the form of algorithms on the computer Illiac I of the university of Illinois. It is about Illiac Suite for String Quartet, whose three movements are carried out this year by the string quartet WQXR. In a famous structure, published in 1959 and which supports the title of “Experimental Music-Composition with year Electronic Computer”, Lejaren Hiller explains in detail the procedures that it applied to the Illiac computer in order to produce the partition of his string quartet.

To locate this period, it is as into 1956 as John McCarthy forged the term of artificial intelligence. One year later, max Mathews, researcher at the laboratories of the Bell Telephone, in the New Jersey, a first numerical programmer of synthesis of the sound for the computer IBM 704 writes. Known today under the name of Music I, it is the first of a great family of acoustic compilers; a psychologist, Newman Guttman, generates first a one 15 seconds duration study, In the Silver Scale. It is as into 1957 as the four movements of the Continuation Illiac for String Quartet of Lejaren Hiller are published; the same year is born the primitive version from the famous language of FORTRAN program (FORmula TRANslator). Let us note that during the creation of the work of Hiller by the string quartet WQXR, it is max Mathews which organized a recording, which gave place, thereafter, with the publication of this recording in a disc carried out in 1960 by the Bell Laboratories, and entitled Music from Mathematics: even if the ways traced by these two inventors are independent, it is not known as that they did not cross…

From these two almost contemporary events, the development will continue, gradually, in the traced directions: the composition and production of the sound. We will see low the courses of them. But a third way is not long in appearing: it is born from the same observation that had made Hiller: the computer is above all, at that time, a formidable calculating machine. Moreover, the English term of selected computer indicated, before the appearance of these machines, the employees charged to operate calculations. But at the same time, with a bit of fear, one spoke readily at the time of electronic brains. An artist could not approach the computer not without a certain emotion, which explains without any doubt the attraction sometimes terrifying that data processing will exert on the artists of the following decades. But they are two scientists who are at the origin of these experiments: Hiller practiced chemistry, while Mathews was an already famous researcher. It is undoubtedly what explains remarkable methodologies that they reflect in place, each one on their side, and with completely independent aims.

With the Bell laboratories, max Mathews, on his side, written in 1957 a first numerical programmed of synthesis of the sound for the computer IBM 704, equipped with 4096 words of memory. Known today under the name of Music I, it is the first of a great family. The program Music III (1960) introduced the concept of instrument modular. The model imagined by max Mathews is inspired more than one equipment of laboratory or an electronic studio of music that by an acoustic stringed-instrument trade. The program offers a range of independent modules (Unit Generators), in charge each one of an elementary function: oscillator with form of programmable wave, adder of signals, multiplier, generator of envelopes and random signals, etc… The musician builds a “instrument” by connecting a selection of modules between them. The signals produced by the oscillators or the generators are led towards other modules there to be modified or mixed. Several instruments can be joined together within a “orchestra”, each instrument having its own identity. Contrary to what occurs in the material universe, it there not of limit to the number of modules usable simultaneously, except perhaps the memory of the computer. The result of the placement of the instrument is the progressive calculation of the sound in the form of a sequence of numbers which, put end to end, represent a complex sound wave. These numbers are called “samples”. Today, the number of samples representing one second of its was established to 44 100 per channel for the applications general public, and to 48 000 for the professional field.

Because of relative slowness of the machines and design weight to be carried out, time put to generate the sound wave is quite higher than the duration of the sounds; the operation of these programs is known as “in differed time”. With the origin, the sound waves calculated in numerical form were stored on a numerical tape progressively proceeding end of an arithmetic unit of samples. This mode of production of the sound is called “direct synthesis”. Thus creates for itself a “file of sound”; once completed, the musician calls upon a second program, charged reading the file of sound in real time and with sending the samples towards a digital-to-analog converter, which is connected to an amplifier and loudspeakers.

To activate the orchestra, the musician must write a “partition”, in which all the parameters claimed by the modules of the instrument are specified. This partition is presented in the form of a list of numbers or telegraphy codes, each “note” or a each event being the subject of a particular list. These lists are ordered in time.


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