As applied to music, the word “chromatic”, derived from the Greek word for color,is typically used in one of two ways:
(i) to describe notes that fall outside the seven-note scale associated with each of the twenty-four major or minor keys;
(ii) to describe a twelve-note scale that contains all the notes available in the Western pitch system (i.e., a scale that uses all the “white keys” and all the “black keys”). A chromatic note is indicated in music notation using a set of symbols called “accidentals placed beside notes to indicate how they should be inflected – typically raised (“sharped”) or lowered (“flatted”). (An earlier method used to indicate accidentals involved notating inflected pitches in colors other than black – a practice reflecting the origins of the use of “chromatic” for scales containing these inflected pitches. ) Here are the C major scale and a chromatic scale that begins on the note C.
C Major Scale
Chromatic Scale that begins on the note C
For an illustration of the first meaning, we might imagine some modified versions of the Yankee Doodle melody:
In the example below, the note D has been replaced with one of its chromatic inflections: D has been replaced with D#. The “#” symbol (called a sharp) indicates that a note is to be played one half step higher than in the original version. Because the note D# does not belong to the key of C major, it is considered a chromatic alteration of the melody. Indeed, knowing how the tune “ought” to sound, the funky sound of the D# sounds accidental.
Yankee Doodle with D sharp
In the following example, the note D has been chromaticized in a different way. The skewed “b” symbol (called a flat) indicates that the note is to be played one half step lower than in the original version.
Yankee Doodle with D flat