In
music, a
pitch class (
p.c. or
pc) is a
set of all
pitches that are a whole number of
octaves apart, e.g., the pitch class C consists of the Cs in all octaves. "The pitch class C stands for all possible Cs, in whatever octave position." Important to
musical set theory, a pitch class is, "all pitches related to each other by octave, enharmonic equivalence, or both." Thus, using
scientific pitch notation, the pitch class "C" is the set