CHROMATIC, a kind of music which proceeds by several semitones in succession. The word is derived from the Greek γ^ο>μa, which signifies colour. For this denomination several causes have been assigned, of which none appears certain, and all are equally unsatisfactory. Instead, therefore, of fixing upon any, we shall offer a conjecture of our own, namely, that as χjw∕xα not only signifies a colour, but also a shade of a colour by which it melts into another, or what the French call nuance, so the word in this sense is highly applicable to semitones, which being the smallest interval allowed in the diatonic scale, most easily run into one another. In order to learn the reasons assigned by the ancients for this denomination, and their various divisions of the chromatic species, the reader may consult the same article in Rousseau’s Musical Dictionary. At present this species consists in giving such a procedure to the fundamental bass, that the parts in the harmony, or at least some of them, may proceed by semitones, as well in rising as in descending, which is most frequently found in the minor mode, from the alterations to which the sixth and seventh notes are subjected, by the nature of the mode itself.

The successive semitones used in the chromatic species are rarely of the same kind, but alternately major and minor, that is to say, chromatic and diatonic; for the interval of a minor tone contains a minor or chromatic semitone, and another which is major or diatonic, a measure which temperament renders common to all tones; so that we cannot proceed by two minor semitones which are conjunctive in succession without entering into the enharmonic species, but two major semitones twice follow each other in the chromatic order of the scale.

The most certain procedure of the fundamental bass to generate the chromatic elements in ascent, is alternately to descend by thirds and rise by fourths, whilst all the chords carry the third major. If the fundamental bass proceeds from dominant to dominant by perfect cadences avoided, it produces the chromatic in descending. To produce both at once, the perfect and broken cadences are interwoven, but at the same time avoided.

At every note in the chromatic species, the tone must be changed; that succession ought to be regulated and limited, for fear of deviation. For this purpose it will be proper to recollect that the space most suitable to chromatic movements is between the extremes of the dominant and the tonic in ascending, and between the tonic and the dominant in descending. In the major mode one may also chromatically descend from the dominant upon the second note. This transition is very common in Italy; and, notwithstanding its beauty, begins to be a little too common amongst us.

The chromatic species is admirably fitted to express grief and affliction; and these sounds boldly struck in ascending are powerfully effective. Their influence is no less magical in descending; it is then that the ear seems to be pierced with real groans. Attended with its proper harmony, this species appears proper to express every thing; but its completion, by concealing the melody, sacrifices a part of its expression; and for this disadvantage, arising from the fulness of the harmony, it can only be compensated by the nature and genius of the movement. We may add that, in proportion to the energy of this species, the composer ought to use it with greater caution and parsimony, like those elegant viands which, when profusely administered, immediately surfeit us with their abundance, as much as they delight us when enjoyed with temperance and moderation.

Chromatic, Enharmonic. See Enharmonic.