Link to presentation directly.

• Many music libraries use the Library of Congress classification system for assigning call numbers to books and scores.
• Most Library of Congress call numbers have at least two lines:
• The first line will be a letter (or letters) that represents its subject area and, in music a bit about format as well.
  • M = music scores
  • ML = books of literature on music
  • MT = books of music instruction and study
• The second line - the one with numbers - represents the specific subject within the larger subject area. For example piano sonatas (23) within the larger classification of scores (M) are represented by M 23.
• The next number, referred to as the Cutter number, reflects a letter/number combination that the library has developed to indicate the author (or sometimes the topic).
• For example, in the M23 section, Haydn is represented by the Cutter number .H41. This means Haydn's piano sonatas would be shelved together in the section:

M
23
.H41

• Sometimes, Cutter numbers will be followed by other information to help distinguish one item from another. Examples of additional information that might appear after the Cutter number include volume number, copy number, part name (such as trumpet or piano), or opus number.

• Let's consider an example:
  • ML410.A638 A3 1945
  • Author: George Antheil
  • Title: Bad Boy of Music
  • An autobiography by George Antheil
     
  • ML
    (The first two letters, ML, mean this is a book that contains literature on music.)
  • 410
    (The 410 here indicates a commonly used subject designation, composer biography.)
  • .A638
    (The Cutter number is A638, which is the Cutter number that will be used for all books by George Antheil located in this section.)
  • A3
    (In this example, A3 is a second Cutter number that refers to the subject matter [also George Antheil].)
  • 1945
    (1940 is the year of publication for this book, and its inclusion in the call number differentiates this book from other editions of the same book)
• There are some basic rules that dictate how LC call numbers are put into order:
  • Shelve titles alphabetically by the first line of the call number.
  • If the first line is the same, the second line determines the order of call numbers.
  • Read and sort the numbers in the second line as whole numbers.
  • If you see a decimal point (even before a letter), read each of the following numbers separately, not as a whole number.
  • When other things are equal, numbers come before letters.
  • Opus numbers and volume numbers are sorted alphabetically. Treat opus numbers as whole numbers.
  • And finally, nothing always comes before something.