OF OTHER CliORDS OF THE SEVENTH: THF.1R PREPARATION AND RESOLUTION ANALOGOUS TO THE PERFECT CA DENCE.
125. If to the minor common chord of the second of the scale major mode, we add the key-note, we have a chord consisting of minor third, perfect fifth, and minor seventh, No. 1; of which chord Mr. Shield observes, that it is a chord less agreeable to the ear than the dominant chord, more restricted in practice, but not less essential to a regular stream of harmony.
The seventh in this chord must be prepared in the pre ceding chord. It resolves after the sante manner as the dominant chord, that is, by the diatonic descent of the ith on the major third of the dominant chord, and the ascent of the bass by fourth, or descent by fifth ; but the interval be tween the third and seventh being perfect fifth, that third is not necessarily constrained to rise to the octave like the lead ing note in the dominant seventh; No. 2. From its resolu tion on the dominant, it may very well be called the sub dominant chord of seventh.
This name of subdominant chord, however, is chiefly given to its first derivative, when the third of the chord, that is, the fourth of the key, is made bass ; No. 3. This chord consists of major third, perfect fifth, and major sixth ; or of a major sixth added to the common chord of the fourth of the key. But the 5th of the chord is the discord, which must be prepared, and resolved by descending semitone on the major tItird of the dominant chord; No. 4. This chord is called by some the groat sixth, and it is figured 5 These two forms of the chord, viz. the 7th on the second 6 of the key, and the on the fourth, are those chiefly in use, 5 the latter even more frequently than the former; and both the progressions to the dominant are used as cadences to terminate phrases. It has been much disputed, whether the second or the fourth of the key is to be reckoned the funda mental. The question is of very little importance, as the manner of employing the chords is no way influenced by it.
The whole conibination, as we former]) observed, is made up by the union of the common chords of the second and, of the fourth of the key.
The 2d derivative, when the fifth of the chord of 7th is put in the bass, consists of minor third, perfect fourth, and minor sixth; No. 5. This inversion is much less frequently used than the preceding.
The third derivative, when the discord is in the bass, is more fiequently met with than the last, though much less 6 frequently than the It consists of major second, perfect 4t11, and major sixth, and is figured by 4„, No. 6.
126. After the same manner, in the minor mode a seventh, which is the key-note, is added to the imperfect common chord on the second of the key, No. I; and it consists of minor third, false fifth, and minor seventh. It is figured ;( the dash through the 5 intimating that it is imperfect.
This seventh is generally prepared, and it resolves in a similar manner on the dominant chord, No. 2.
Its first derivative, which consists of minor third, perfect fifth, and major sixth, figured in like manner resolves on 5' the dominant, No. 3.
In all these cases, both in the major and minor modes, the dominant on which the subdominant chord thus resolves, may have its added seventh, though omitted in these exam ples.
Its second derivative, when the 5th is made bass, consists of major third, major fourth, and major sixth, No. 4. Its third derivative consists of major second, perfect fourth, and minor sixth, No. 5.
This chord and its derivatives, we shall afterwards find, are often treated as belonging to the dominant chord of the elative major mode. The chord of the seventh and the first derivative are treated both ways, e. are resolved either into the dominant of the minor niode, or into the tonic of the relative major; the second derivative used chiefly in 'this last way ; and the 3d derivative chiefly as the subdomi nant of the minor, resolving on the first inversion of the dominant, No. 6.