The order of the pitch classes can be determined by the circle of fifths.

Thus, a pitch class's nearest neighbors and itself form perfect fifth and major third intervals.

The specific pitch classes belonging to Class(i) are then called specific intervals.

Performing a retrograde operation upon the pitch class set 01210 produces 01210.

Only one of these labelings is sensitive to the (arbitrary) choice of pitch class 0.

It is also very common to label pitch classes with reference to some scale.

Accents are placed on single notes that trade off between the instruments creating a sense of shifting, but still using the same pitch class.

The (or aggregate) is the set of all twelve pitch classes.

Or a larger set of underlying pitch classes may be used instead.

Because of that, all notes with these kinds of relations can be grouped under the same pitch class.