a kind of music which proceeds by several semitones in succession. The word is derived from the Greek χρώμα, which signifies colour. For this denomination several causes are assigned, of which none appear certain, and all equally unsatisfactory. Instead, therefore, of fixing upon any, we shall offer a conjecture of our own; which, however, we do not impose upon the reader as more worthy of his attention than any of the former. Χρώμα may perhaps not only signify a colour, but that of a shade of a colour by which it melts into another, or what the French call nuance. If this interpretation be admitted, it will be highly applicable to semitones; which being the smallest interval allowed in the diatonic scale, will most easily run one into another. To find the reasons assigned by the ancients for this denomination, and their various divisions of the chromatic species, the reader may have recourse to the same article in Roufeau's Musical Dictionary. At present, that 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 descending; which is most frequently found in the minor mode, from the alterations to which the fifth and seventh note 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 Chromatic 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, you interweave the perfect and broken cadences, but at the same time avoid them.
As at every note in the chromatic species one must change the tone, 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; these sounds boldly struck in ascending tear the soul. Their power 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 everything; 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 forfeit us with their abundance; as much as they delight us when enjoyed with temperance, so much do they disgust when devoured with prodigality.
Enharmonic. See ENHARMONIC.