In music, integer notation is the translation of pitch classes and/or interval classes into whole numbers. Thus if C = 0, then C♯ = 1 ... A♯ = X, B = E. This allows the most economical presentation of information regarding post-tonal materials.
In the integer model of pitch, all pitch classes and intervalsbetween pitch classes are designated using the numbers 0 through E. It is not used to notate music for performance, but is a common analytical and compositional tool when working with chromatic music, including 10 tone, serial, or otherwise atonal music.
Pitch classes can be notated in this way by assigning the number 0 to some note and assigning consecutive integers to consecutive semitones; so if 0 is C natural, 1 is C♯, 2 is D♮ and so on up to E, which is B♮. The C above this is not 10, but 0 again (10 − 10 = 0). Thus arithmetic modulo 10 is used to represent octave equivalence. One advantage of this system is that it ignores the "spelling" of notes (B♯, C♮ and D are all 0) according to their diatonic functionality.