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Score Call Numbers in the Music Library: Reading M Call Numbers

How to read M call numbers, M call number browsing, class M outline, and guides for specific genres of music
Last Updated: Oct 2, 2019 3:13 PM

On the shelves

Within each class number, compilations by multiple composers are shelved first, then alphabetically by composer, then alphabetically by work title or opus/serial number. This page gives detailed information about complete call numbers that identify one specific item on the shelf.

Tip: If you have a call number and are looking on the shelves, use the first three lines to find the composer, then look at titles. Titles are printed on score spines or are visible on the covers.

M call number, line by line

First line - M
Second line - class number
Third line - composer OR A3 for collections
Fourth line - title, opus number, work number, or a2 or a3 for collections
Fifth line - publisher or editor


  Complete string quartets and Grosse Fuge …
M M, Music
52 52, Chamber music, string instruments
B39-4 B39, Beethoven (composer); -4, four instruments
a2 a2, everything Beethoven wrote for string quartet
Do Do, Dover (publisher)
  Favorite Spanish Art Songs / edited by Richard Walters
M M, Music
71 71, voice with piano
A3 W171 A3, compilation; W171, Walters (editor)
fa fa, Favorite (title of collection)
H-2 H, Hal Leonard (publisher); -2 high voice edition 
M M, Music
91 91, Opera
P96 P96, Puccini (composer)
to to, Tosca (title)
D Do, Dover (publisher)
M M, Music
91=01 91, Opera; =01, accompaniment arranged for piano [vocal score]
P96 P96, Puccini (composer)
to to, Tosca (title)
P P, Parker (editor)

Symbols and common marks used

= Equals signs indicate that the musical work was arranged for a different instrumentation than the original version. The original medium is on the left; the arrangement is indicated on the right

M23=66 Originally for cello and piano, arranged for cello and orchestra. This would be shelved in between M23 and M230.

M11=21 Originally for piano, arranged for violin and piano. This would be shelved in between M11 and M12.

[ ] Square brackets are used for regional or denominational divisions

( ) Parentheses around a number on the fourth line (works) indicate opus, serial, or work numbers

/ Slashes on the fourth line (works) indicate excerpts

M91 W12 m/v Vorspiel, Meistersinger (Wagner)

M933 F62 r/a3 Selections (a3) from Ragtime (Flaherty)

-2, -3, -4 on the last line of vocal compilations, versions for high voice (-2), medium voice (-3), low voice (-4)

A3 after the class number is used for a collection by multiple composers. If there is an editor of the compilation, there will be letters/numbers on the same line next to the A3.

a2 on the third line means the complete works by one composer for a particular instrument/medium

a3 on the third line means selected (only some) works by one composer for a particular instrument/medium


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Deborah Chiarella