Chromatic scale

What it means

The chromatic scale runs through all twelve semitones of the octave in succession. Since all the steps are the same size, no note stands out from the others: it has no centre and no root but is an even grid. In this it differs fundamentally from the diatonic scale, whose uneven distribution of whole tones and semitones first produces a tonal gradient at all.

In the notation

There is a common rule for the spelling: ascending, the intermediate notes are as a rule written with sharps, descending with flats, because this depicts the direction of movement. It is not binding, however — the harmonic context may call for a different spelling, for instance when a note is to be understood as the altered degree of a chord. In such cases function takes precedence over convenience.

Musical use

As a scale, the chromatic scale rarely appears as the basis of a piece, but often as a running figure, as a connection between goal points, and as a means of intensification. Chromaticism in the wider sense — individual notes foreign to the scale within a diatonic frame — is by contrast omnipresent.

In the twentieth century the even twelve-note space became the basis of compositional procedures of their own, in which the equal rank of all notes is not a deficiency but a prerequisite. The complete equality of the semitones, however, is first produced by equal temperament; in unequal temperaments the steps are of different sizes.

In notation, the chromatic scale is usually written with sharps ascending and flats descending so that the leading-tone direction stays clear. In major–minor contexts the spelling often follows the key: notes of the scale keep their names, and the chromatic intermediate degrees are notated so that they make harmonic sense. As the material of twelve-tone technique, by contrast, the scale loses all reference to a root.

Performance practice

Practise chromatic runs for evenness — they easily fall apart into unequal steps, especially at places where the fingering changes. Count in groups instead of note by note so that the movement keeps its flow. And read the accidentals as a direction indication: sharps usually point upward, flats downward.