. REQUIRE "ipub2" SOURCE_FILE;
In computer music one takes the analog phenomenon of sound production
and applies digital principles to it via the ultimate digital vehicle --
the computer.  Sound may be translated to an analog (voltage) signal in
a wire -- as, for example, in a stereo.  Similarly, this signal may be described
by numbers, thus allowing the sound to be manipulated by the computer.
The involvement of number manipulation and theory take this field far beyond the
realms of computer science and music alone. The disciplines of mathematics,
engineering, and physics (specifically acoustics) are inextricably involved
in computer composition. 

The cataloguer with no technical background faces a frustrating dilemma.
Since computer music draws equally from all the above-mentioned disciplines,
there is an obligation to explore some technical as well as general 
materials.  Musicians will eventually have to peruse technical literature
in order to fully realize the potential of a powerful medium.
Pinpointing specific areas within the technical fields 
which have musical applications was difficult.

The bibliography was set up according to the following subject
areas: ⊗⊗Acoustics⊗, ⊗⊗Bibliographies⊗, ⊗⊗Composition
software⊗, ⊗⊗Digital signal
processing⊗, ⊗⊗Journals⊗, ⊗⊗References⊗, ⊗⊗Synthesis techniques⊗.

A brief word on the category of ⊗⊗Synthesis techniques⊗ may be of aid.  These
are techniques used to vary the quality of a sound signal, and may be broken
up into three areas: 1. Additive (adding sinusoidal waves together) 
2. Subtractive (use of digital filters to carve away part of a signal)
3. Non-linear (none of the above -- techniques such as frequency modulation 
and waveshaping)

The most helpful LC classification areas are: ⊗⊗ML1092⊗ (Music history & crit. on
electronic instr.), ⊗⊗ML3800-ML3817⊗ (Music acoustics & physics), ⊗⊗MT41⊗
(Textbooks of composition by mechanical means), ⊗⊗MT723⊗ (Electronic instrumental
techniques), ⊗⊗QC240-QC246⊗ (Physics, sound), ⊗⊗TK5102.5⊗ (Telecommunication,
Signal processing--Digital techniques), ⊗⊗TK7868.D5⊗ (Electrical engineering--
Special circuits--Digital), and ⊗⊗TK787.2.F5⊗ (Electrical engineering--Photoelectric
devices--Filters)

The most helpful Dewey classification areas are ⊗⊗781-789⊗ (Music--General principles
and considerations), ⊗⊗001.6-001.64⊗ (Computers), and ⊗⊗620-621⊗ (Engineering & allied
operations, applied acoustics)

Important LC subject headings are: ⊗⊗Computer music, Computer composition, 
Computer sound processing, Electronic music, Music - Acoustics and physics,
Signal processing - Digital techniques, Digital filters (Mathematics),⊗
and ⊗⊗Psychoacoustics.⊗

.next page;
Clearly, for computer music works with purely musical applications, the
Library of Congress subject headings and classes are inadequate.

For classification purposes,
technical works must be lumped into the catch-all class MT41 which
contains everything from simple-minded 18th century compositional games
to sophisticated computer software controlling performance as well as
compositional structure.  They may also be put in the equally unsatisfactory
ML1092 which was originally conceived for techniques involving manipulations 
of magnetic tape, or MT723 (instrumental techniques--electronic instruments)
(I am uncomfortable classifying computer music works in categories involving
the term "electronic", first because of LC's definition of electronic
music, and second because it seems to imply analog techniques rather than 
digital) All musical scores are jammed into the category for 
electronic music despite the fact that they do not fit the definition
established by LC.  

The alternatives for the literature are 1. to use the class ML63 ("Topics not
elsewhere provided for") -- a somewhat cowardly way out, or 2. lose the
music identity altogether and classify the works in the more established 
fields whose techniques are involved and more clearly defined by LC (i.e.
Computer science, Mathematics, Physics, and Engineering)  There are no
alternatives provided for scores.

The "specific" subject headings boil down to ⊗⊗Computer music, Computer composition,⊗
and ⊗⊗Computer sound processing⊗, all of which may be applied to any work on
computer music, since, as I pointed out before, the machine simultaneously
fulfills the role of performer, instrument,and compositional medium.

The problem with the subject heading and classification schemes for
computer music then,is that they do not allow enough specificity.  Computer
music is a relatively new interdisciplinary art.  For this reason, very few
provisions have been made for the classification of its various components,
probably because its full extent or potential has not yet been realized.
This makes for frustrating and somewhat boring cataloguing.  Hopefully the
situation will be alleviated as the compositional movement becomes more
established.