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classical music cataloging systems explained
At their most basic, there are only two kinds of composer catalogs: 1) thematic, and 2)
Informal lists of composers' works.
A theme is a subject of discourse,
discussion, meditation, or composition. In music, a thematic catalog
is a list of compositions in a collection of a single composer, usually
arranged in order of opus number or some other specific numbering scheme
(i.e., BWV numbers for Johann Sebastian Bach in the catalog by Schmieder, where B stands for
Bach; K. numbers for Mozart's music, where K. stands for Köchel,
the cataloger of Mozart's music; etc.). Incipits (see thematic
Catalog Terminology, below) are often included
to positively identify a work.
Perhaps without exception, thematic catalogs are created by catalogers with musicological
training—by scholars. To be worthy of its name, a thematic catalog must
be a thorough and comprehensive listing of a composer's works, sometimes
including biographical studies or other information. The cataloger's goal
is to compile as complete and as error-free an account as possible of a composer's works given what is known
publically to musicology at the time of compilation and what is known
privately to the cataloger as the outcome of his personal researches.
Creating thematic catalogs is an exacting undertaking demanding
scholarship because reliable historical information about a composer or
his works may be difficult or
impossible to obtain and because the accuracy of the data in catalogs
must be beyond reproach wherever circumstances allow. These data must be
correct and complete because they are used as a
basis for the publication of critical editions of musical scores, for
historical studies of composers' lives and works, and for analyzing the
music itself so as to make visible the composer's precise musical
- Literally hundreds of thematic catalogs have been created over the
centuries by literally hundreds of catalogers, catalogs that list the
works of literally hundreds of composers. To quickly get an idea of some
of the most prominent ones, see a list of some of their names at the
MUSIClasical.com web site:
thematic Catalogs online?
The Muse Of Music knows of no thematic catalog that is available online at
this time; all extant thematic catalogs come in the form of printed
documents. However, some online catalogs approach the quality and
comprehensiveness expected of a thematic catalog, especially those
published at university web sites.
If you know of exceptions, please contact The Muse Of Music.
informal lists of composers works
Informal lists of composers' works are lists of that do not conform to
the rigid scholarly requirements of a thematic catalog; hence they are
Informal catalogs share a common primary objective with thematic
catalogs, namely to list the works of a single composer; but the lists of
works in most informal catalogs may not be complete; the citations may not
be as accurate; the listed works may not be elaborated with as much
supplementary information or with the same kinds of information; and the
lists may be out-of-date or defunct.
- To quickly get an idea of what informal lists of composers works are
like, visit the page titled Works Lists at the ClassicalNetTM
web site. It contains a list of the names of composers, each conjoined
with the name of his cataloger. Once you arrive at this page, click a few
of the composer's names. Each click will take you to a page at the
ClassicalNetTM web site or at another web site that contains a
catalog for that composer that was created by the named cataloger:
Most if not all of the catalogs named on this list of catalogs are
informal. Notice that many of them no longer exist; they are defunct. Some
of them list two or more catalogs for the same composer. (The Muse
suggests that you check to see whether the catalogs agree with one another
in cases where more than one catalog is listed for the same composer.)
Many informal catalogs are modeled after thematic catalogs in one key
respect: they incorporate a numbering system borrowed from a popular
thematic catalog. For example, an informal catalog which lists Schubert's
works is likely to identify each listed work by the same number that is
employed by Deutsch in the Deustch thematic catalog. In such a catalog,
Schubert's Quintet, D.956 might be identified by the
number D.956, the same number and catalog designator as cited by Deutsch. It
might (or might not) also contain the popular name of a work. For example,
it might or might not list Schubert's Symphony No. 8 as the Symphony No. 8
in B minor, D.795, known as The Unfinished Symphony.
Informal lists come in many shapes and sizes: they come as web sites;
they come as books; they come in books, as sections, chapters, or
appendices of a larger work about a composer, musical period, musical
style, or movement; and they come as notes, footnotes, or appendices. they
appear in almost any kind of printed form or medium.
Why informal lists? Most informal lists are compiled by classical music
lovers, armchair musicologists, authors, classical music loyalists, fans of a
specific composer, organizations that seek to promote a particular
composer's music for various reasons, classical music popularizers,
backers of specific classical composers, and by composers who seek to
promulgate and promote their own compositions; even
businessmen, national groups, and others get in the
with primary agendas or vested interests other than scholarship alone.
Many of the lists of composer's works found on the Internet are of this
variety. For example, one can find informal lists on the Internet that are
compiled by a French cultrual organization to promote French culture, by a
similar Spanish cultural organization, and by a promoter of Soviet
classical music (yes, Soviet, not Russian). A number of web sites offer
informal lists of composers' works as a courtesy to music lovers and to attract
visitors who are likely to buy the recordings they sell in the Virtual Mall, a not-so-hidden agenda.
thematic catalogs and informal lists compared
Compared with thematic catalogs, informal lists have distinct advantages
and disadvantages. Despite a typical lack of scholarly authority or
comprehensiveness, informal lists tend to be handy and easy for the
casual observer to use and understand. If on the Internet, they are likely
to be easier and lest costly to access, and in many cases their listings can be searched
with a browser.
Informal catalogs on the Internet are
more likely to offer a computer-generated index of one sort or another, and
they might even offer multiple indexes for a single composer's works or multiple lists of for
multiple composers, each list organized in a different way. In a
hypothetical example, a J.
S. Bach catalog might be sorted by BWV number, date, opus number, and the
name of the piece. A catalog of Vivaldi's works might be arranged by the
names of multiple Vivaldi catalogers (e.g., Ryom number, Fanna number,
Pincherle number, and Ricordi number), opus number, instrumentation, and
type of music (e.g., opera, instrumental).
Most thematic catalogs contain only a single listing, while many
informal catalogs contain multiple listings. These facts are easy to
reconcile with one another when one considers that most thematic catalogs were created before the advent of computers,
when printing was the only practical publication medium; but most informal
catalogs, which are relatively recent developments, were created after the
advent of computers and are published at web sites, where computers are involved in their preparation.
thematic catalogs vs. Informal
Except as otherwise indicated, much of what can
be said for thematic catalogs applies to informal lists of composers works
to one degree or another. Please keep this fact in mind as you read the
sections that follow on this page.
There is no standard way to organize a catalog of
musical works. As a consequence, no two catalogs
are exactly alike; each is unique.
Normally, a thematic catalog will contain, at a minimum:
- Name of a work. For example, Dvorak Symphony #3.
- Poplar name of a work. (Dvorak's String Quartet No. 12 is nicknamed
- Musical description—For example, musical form (e.g., sonata,
symphony, opera); number and kind of instruments or voices scored
(e.g., two pianos, orchestra, orchestra and chorus); key; movement
- Associated information that serves to identify
the work—For example, an incipit, a
description of when or where the work was composed,
names of co-composers, names of librettists, etc.
- Opus number—A number that normally conveys the order of publication
(see Thematic Catalog Terminology, below).
- Publication date.
- Work number—An ordinal number which indicates the sequence in which the
composer created a specific work in comparison with other works of a
similar nature. For example, piano concerto No. 2, etude No. 4. (see
Thematic Catalog Terminology, below)
- Catalog number—the ordinal number assigned by a cataloger that
designates the order in which a work was created by a composer as compared
with all his other works.
how thematic catalogs work
By custom, a single cataloger (or perhaps, two or more catalogers
together) compiles as complete a list as possible of the works of a single
composer. By tradition and for obvious reasons, such a catalog usually takes the name of the
composer, not the person who compiles the catalog.
How opus numbers are assigned to composers'
Each work in a typical catalog bears a number called an opus
number (work number), a unique mark that identifies each specific work created by a single composer or
his collaborators. The opus number is usually assigned by the
publisher at the time a work is published; if not so assigned, it's assigned by the person
or group who creates (compiles) a catalog of a composer's works, a person
referred to as a cataloger or compiler.
The publisher or cataloger assigns this opus number to
each work to identify it for posterity. The number is a sequential number
that is usually assigned in the chronological order of publication, not
the order of composition. In this connection, the word opus is used
to denote a particular musical composition; and the catalog number,
publication number, and opus number are usually, but not always, the same, a
circumstance which can potentially create confusion.
Why not always the same?
Most often, composers and collaborators choose to create and publish one
new piece of music at a time, as soon as practicable after a work is
finished; they want to meet a deadline, collect a fee, or obtain
recognition. In cases like these, the opus number is unique and no
confusion arises because the printed document that contains the new score
contains a single piece of music.
In cases like these, typically a publisher assigns a single, unique opus
number to the composition at the time of publication. Notice that the
unique opus number assigned to a work is synonymous with the name of the
document that contains the score because the score's opus number is printed
on the face of the document; the score and the printed document are
universally identified with each other because they carry the same number.
No confusion arises because the document title and the opus number are
But confusion potentially does arise when composers and collaborators
choose to publish more than one work in the same document. This can happen
for a multitude of reasons: when a composer chooses to combine the
publication of completely separate works that he's composed at different
times; when a composer publishes separate but related pieces such as
several pieces belonging to the same suite or several overtures for the
same opera or play; when there are several musical accompaniments for acts
in the same play; or for a number of other reasons.
In situations like these, a publisher has two choices: either he assigns
a separate and unique opus number to each work published in a document, in
which case the document cover must display all of the different opus
numbers if it is to represent them; or, he assigns the same opus number to
all the works in the document, in which case the document cover must
display only a single opus number; and then each of the works is not
uniquely represented on the cover.
In circumstances like these, publishers usually take the middle ground.
They assign one opus number to the document and another, unique opus
subnumber or sequence number to each of the works contained within. The
opus number on the document cover uniquely identifies the group of works and the work subnumber distinguishes one work from another.
This policy enables a single
document to use one opus number to represent all the works published by a
single composer at a given time, thus providing unequivocal cover
recognition for the group of works the document contains and rendering the
document synonymous with all the works therein.
It's important to realize that, in cases like these—when
multiple works are published in the same document at the same time—the
opus number, which by definition represents a single musical composition,
actually represents a group of related compositions. The group opus number
is considered to be synonymous with an entire single musical composition,
not the individual pieces.
How opus numbers are assigned to specific works—listing
Each entry in a catalog provides information about each specific work,
information which uniquely identifies and describes the work. Some of the items of information that typically
- formal name of work
- popular name of work (if any)
- musical key
- date of publication
- co-composers (if any)
- author of libretto (if an opera or choral work)
- dedication (if any)
of ensemble for which a work is written (if written for group or orchestra)
- solo instrument(s) for which written (if the work features a solo
instrument), and more.
A code is normally added to or associated with the number assigned to
each work cited in the catalog. This code identifies the catalog in which
the composer's works are numbered.
So, for example, the selection you hear when you open The Muse Of Music's
home page is cataloged as Schubert's Quintet, D.956, where the D. is an
abbreviation of the word Deutsch. Deutsch is the name that
denotes the catalog; it is also an abbreviation of the last name of the
person who compiled the catalog. The number 956 refers to the fact that Schubert's quintet is
the 956th of Schubert's works that have been created, as cited in Deutsch's catalog.
Most, but not all, catalog names take their names eponymously from the
name or names of the catalogers; and the abbreviations of these catalog
names are taken from the initials of the catalogers. Thus the initial D. is
an abbreviation of both the catalog name and the cataloger's name, Deutsch.
The composite of the catalog identifier code and the catalog number is
sometimes referred to as the listing number because it is the number
by which the composer's work is listed in the named catalog.
Why note a catalog's listing number? Once you know a work's catalog
and sequence number, you are in a position to look up the information
recorded by the cataloger in his catalog.
Why knowing a catalog's
listing number is useful
The information in these catalogs is often quoted when a piece is
broadcast on the radio or played in a concert hall. Catalog number is rarely
omitted from the typical printed musical program distributed at a
concert performance. It is common practice to cite the cataloger's name when
announcing the opus number or other cataloged facts about a musical work. Thus,
Scarlatti's Opus 21 might be referred to as Scarlatti Opus 21 in the
Kirkpatrick catalog, or with some similar designation in another catalog, to clear up any
questions about the source of the information.
Professional musicians have come to regard music catalogs as
necessary. Most are authoritative, definitive compilations;
scholars rely on them as authoritative sources for their research. they
are in widespread use today as standard musical references and they rely on them
for scholarly research.
These catalogs are so well established in
the minds of musicians and listening audiences, it is common practice to
abbreviate the cataloger's
name using a code derived from the cataloger's initials, although this is not
always the case. Thus, a designation such as Mozart's Opus 351 in the
Kochel catalog might well take a form such as, Mozart's K 351 (with K standing for the compiler Kochel's catalog and 351 standing for the
publication sequence number assigned by Kochel).
thematic catalog terminology
As you read thematic catalogs or as you read about catalogs you are
likely to encounter a few specialized terms use by musicologists and
musicians. Here are a few such terms, some of which are abbreviations and some
of which are not, with
definitions and supplementary explanations that may help you decipher what
Perhaps the most fundamental term that comes up in connection with the
subject of music catalogs is the word thematic. Most, but not all,
music catalogs are thematic catalogs.
Music catalogs that are thematic catalogs are called thematic because
they aim to include the musical notation for the principle themes or tunes
of each work they list. These notes are meant to serve as an aid in
identifying the works. They do this by means of an incipit. See a
definition and an explanation for the term incipit, below.
A work number is an ordinal number that
indicates the order in which a composer has created a specific work in
comparison with his other works of the same kind.
Work numbers are assigned to a composer's works in the sequential order
in which the composer has written works of a similar type. For example,
usually a composer will write his Symphony No. 4 before he writes his
symphony No. 5 or his piano concerto No. 2 before he writes his piano
concertos No. 3, No. 4, or No. 5.
Work numbers are normally assigned to a composer's works by catalogers
rather than by composers. theyare almost always present in a classical
- Thematic catalog number (also sometimes referred to as work number)
A thematic catalog number is an ordinal number assigned to a
specific work in a catalog which indicates the order in which a composer has created the work in
comparison with all his other works, regardless of their type. The thematic
catalog number for a specific work is unique; it differentiates each work
written by a composer from every other work.
Thematic catalog numbers are normally assigned to a composer's works by
catalogers rather than by composers. theyare always present in a classical
Thematic catalog numbers are usually expressed in the form of a coding
system that is especially developed by the cataloger for the catalog he is
creating. (In some cases, a cataloger will borrow a coding system devised
by another cataloger.)
The coding system developed by cataloger Martin Ruhnke and published in
his thematic catalog for the works of Telemann titled Georg Philipp
Telemann: thematisch-systematisches Verzeichnis seiner Werke provides
us with an example of a cataloger-developed thematic cataloging system.
Work numbers in Ruhnke's catalog for Telemann are encoded in a format such
as TWV 41:a15. In this example, TWV is shorthand for the name of the
catalog and 41:a15 is the specific, unique work number Ruhnke has assigned
to one of Telemann's works in this catalog. This number assignment sets
this work apart from every other work Telemann has ever written.
Ruhnke has not gone to the trouble of developing this particular
numbering system when a simpler one might do equally well; he has not been
capricious. The historic circumstances under which different composers
create music can be unique; the nature of their output can be unique. Each
composer can pose intellectual and scholarly cataloging problems that are
best solved by a numbering scheme that's tailor-made to suit these factors.
NOTE: 1) A thematic catalog is a catalog of all of a single composer's
works, usually but not always organized by type of music, and arranged in
in chronological order. 2) When new information comes to light, some
catalogs, especially those for composers in whom interest runs high,
undergo revisions and are republished in new editions. Typically, different
editions of the same catalog are noted by decimals, as in KV, K.2, K.3,...,
K.6. In this example, KV stands for Kochel's original catalog, K.1 for its
second edition, etc. 3) A catalog of his own works created by a composer
will often bear the composer's initials, as in MozV, which stands for
Mozart's own directory of his works.
work numbers and thematic
The term work number has two
senses: 1) the thematic catalog number, and 2) the order of a work
compared to other works of the same type.
listed in a thematic catalog will always have a work number assigned to it (sense #1). Sometimes
the description of a work will also contain a work number that indicates
the order of its composition compared with other works of the same type
Don't confuse the two numbers.
- Opus; opus number; op.; or Op
An opus number is a unique number assigned to a composer's work
or group of works, usually in the chronological order of publication. (Opus is Latin for the word
work; and the plural of opus is opera.)
By definition, an opus number represents the order in which a work is published, not the
order in which it is composed. Sometimes an opus number is assigned to a work by its composer, but more
often it is assigned by a publisher. Opus numbers are almost always present in a
classical composer catalog.
WoO is an abbreviation for Werk ohne Opuszahl (German) or
Work without opus number. This term appears in classical music
writings generally, but especially in classical music catalogs. The kinds
of works marked WoO in catalogs are typically unpublished works or groups of works that
have not been assigned an opus number.
An incipit is a kind of musical fingerprint that helps to disambiguate a piece
of music. It consists of a small group of the first few notes, measures, or
lyrics with which a piece of music begins,
notes that are are unique to the piece.
often given in thematic catalogs in order to
positively identify a piece of music. In the case of works with multiple
movements (such as symphonies, sonatas, or suites), an incipit may be
supplied for each movement
or piece a work contains.
Deest is a compound Latin word meaning absent or not
present; desunt is the plural of deest. Deest is derived from two Latin words (de and est) that
have been merged into one (deest), where est means is
and de denotes negation.
The terms deest and desunt are used in musicology generally, but they
occur especially in connection with catalogs of composers' works. If you
see deest in the write-up of a work listed in a catalog, you know
that the work does not appear in another catalog that will be cited in the
write-up. It's not present in the cited catalog.
For example, the comment K. deest occurring in the write-up of a work
listed in a catalog indicates that the work does not appear in the Kochel catalog of Mozart's works, even though it appears
on the page of the catalog
you're looking at. (The Kochel catalog is abbreviated K.). Another
example: BWV deest occurring after a work listed on a page in a catalog you're looking at would indicate that
the work is not present in the Schmieder catalog of Bach's works. (The
Schmieder catalog is abbreviated BWV.)
A verzeichnis is a German word meaning catalog or
directory, as in the term Bach-Werke-Verzeichnis, or Bach Works
Catalog. In the German language, any kind of catalog is a verzeichnis; the
word is not restricted to music.
The term verzeichnis is often seen in connection with composer
catalogs compiled in the German language. Historically, that's because many
composers were German, with the result that many composer catalogers were
Since many recent and contemporary music scholars and musicians of all
nationalities work with these German catalogs, verzeichnis is a word
familiar to them, regardless of their native language; the word has passed
into the general vocabulary of music.
Systems for cataloging classical music—a definition
As explained above, a classical composer catalog may optionally contain these kinds
of codes and numbers:
- Opus numbers, which indicates the accepted publication sequence for a
- Work numbers (sense #1), which indicate the accepted sequence in which a specific
work was created in relation to other works of the same kind.
Also, a classical composer catalog will always contain thematic catalog numbers
(or work numbers, sense #2). Each of these numbers uniquely identifies a specific work and indicates
the sequence in which that specific work was created in the context of the
complete body of a single composer's works. In addition, any particular
thematic catalog number unifies and associates opus
number, work number, and all other pertinent information about a
specific piece, including qualifiers which explain and resolve problems
with opus numbers, work numbers, and other discrepancies, if any.
A system for cataloging classical music is a
particular combination of these codes and numbers.
The encoding systems and numbers for listing a composer's works that appear in a thematic
catalog amount to a system for cataloging the classical music of a single
composer. A given combination of these numbers and numbering schemes
constitute a specific system for cataloging classical music as devised by a
particular cataloger for a particular composer.
The two specific numbering schemes cited above (i.e., Schmieder's BWV numbers
for Johann Sebastian Bach, where B stands for Bach; K.
numbers for Mozart's music, where K. stands for Köchel, the cataloger of
Mozart's music) are examples of numbering systems for cataloging
In the example drawn from Mozart's piano concertos in the discussion of
what can go awry with opus numbers, above, cataloger Kochel sets right the
publication order and work number order for Mozart's piano concertos by
assigning his K. number to Mozart's works.
Because they tend to
be trustworthy, a numbering system devised by a cataloger, such as
Schmieder's numbering system or Kochel's
numbering system, occasionally
comes into common usage in the world of music.
Problems that can occur with thematic catalogs
You may run into problems when you work with catalogs; watch out for
- Here a few of the most important problems and what you can do about
them: click here.