What a Call Number Includes
Library of Congress System
1). All call numbers begin with a letter, which stands for the subject area of the item
M = music scores
-or-
ML = books on music literature
-or-
MT = books on music teaching/music technique
The letters A-L and N-Z may also be found in the music library, since we have books about other disciplines, including ballet, art, history, and citation manuals.
2). Next comes a number prefix. It refers to a narrower subject area.
20 = Solo piano music
M20 is where you find scores for solo piano music
410 = composer biographies
ML410 is where you find music literature/books of composer biographies
655 = percussion
MT655 is where you find music teaching/ technique books for percussion
3). Next comes a decimal point, followed by a letter and a number.
The letter stands for the last name of the composer.
And, since many composers share the same letter (Mozart, Mahler, Mendelssohn), you’ll see a number as well, to distinguish between all these letter-sharing folks
In our library:
M84 = Mozart
M21 = Mahler
M46 = Mendelssohn
M20.M84 is probably a score for solo piano by Mozart
ML410.M21 is a biography of Mahler
MT655.M46 would be a percussion technique book by Mendelssohn, if it existed
(scroll down)
FINDING a CALL NUMBER on the Shelf
Go in order first by the prefix...
M21.M84 comes before
M22.M84
M465.S65 comes before
M556.T85
M25.5.T57 comes before
M26.T57 (watch out for that decimal point: 25.5 comes before 26, right?)
Then, alphabetical…
M21.M84 comes before
M21.S475, which comes before
M21.X34
Finally, by numerical order again
(remember, these are fractions, because there is a decimal point)
M21.M84 comes before
M21.M86, which comes before
M21.M866, which comes before
M21.M9 (remember, .866 comes before .9)
If your call number has yet another set of a letter and numbers, follow the same rules
M21.M84 A27 comes before
M21.M84 B12, which comes before
M21.M84 C42
sometimes an opus (op.) number, copy number (c.), and/OR year of publication might follow. For example:
M1503.R58 P37 1980 c.1
M77.T87 op. 53 1977 c. 2