Pitch class

Set of all pitches that are a whole number of octaves apart

In music, a pitch class (p.c. or pc) is a set of all pitches that are a whole number of octaves apart; for example, 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{Cn : n is an integer} = {..., C−2, C−1, C0, C1, C2, C3, ...}.

This keyword could refer to multiple things. Here are some suggestions: