Books on music in the general collections are all shelved with call numbers starting with M. (This is one of the only classifications where the letter and the subject match up!)
The New Grove Dictionary of Music and Musicians by 
The New Grove Dictionary of American Music by 
The New Grove Dictionary of Opera by 
The Harvard Biographical Dictionary of Music by 
The Harvard Dictionary of Music by 
The Metropolitan Opera Encyclopedia by 
New Penguin Dictionary of Music by The following phrases may be helpful to search as subjects or keyword in the library catalog to find books on the shelves:
You can also search the Subject tab with the names of composers, i.e. Berlioz, Hector
