Oversized books -- See Oversize books Here are entered works on books too large to be shelved in normal shelf sequence. Actual specimens of such books are entered under Oversize books--Specimens, a form heading assigned without geographic subdivision.
Overtone singing -- See Throat singing Here are entered musical works using the vocal technique in which a singer produces more than one audible tone at the same time.
Overture History and criticism -- See Overture Here are entered works about the overture. Musical compositions in this form are entered under the heading Overtures, followed if appropriate by medium of performance.
Overtures History and criticism -- See Overture Here are entered works about the overture. Musical compositions in this form are entered under the heading Overtures, followed if appropriate by medium of performance.
Overtures (Orchestra) -- See Overtures Here are entered overtures for orchestra. Overtures for other mediums of performance are entered under this heading followed by the medium, e.g. Overtures (Chamber orchestra). Works about the overture are entered under the heading Overture.
