Chromatic circle "discrete" structure, and there is no obvious way to assign pitch classes to each of its points. A pitch constellation is a graphical representation of pitches used to describe musical scales, modes, chords or other groupings of pitches within an octave range. It consists of a circle with markings along the circumference or lines from the center which indicate pitches. Most pitch constellations use of a subset of pitches chosen from the twelve pitch chromatic scale. In this case the points on the circle are spaced like the twelve hour markings on an analog clock where each tick mark represents
Transposition (music) Thus the set ("A") consisting of 0–1–2 transposed by 5 semitones is 5–6–7 (T("A")) since , , and . There are two different kinds of transposition, depending on whether one is measuring intervals according to the chromatic scale or some other scale. In chromatic transposition one shifts every pitch in a collection of notes by a fixed number of semitones. For instance, if one transposes the pitches C–E–G upwards by four semitones, one obtains the pitches E–G–B. In scalar transposition one shifts every pitch in a collection by a fixed number of scale steps relative to some scale. For example,