Complete Encyclopaedia of Music/B/Bass, thorough

Bass, thorough, is the art of expressing by figures any combination of notes to be struck with the right hand upon the organ or piano-forte, to any given note in the bass. These figures are a sort of short hand, which describes the accord, and in which is contained the harmony of the full score.

If C is taken as the tonic or key note, the natural harmony belonging to it consists of the third, fifth, and eighth, making the common chord of C, thus:

Common chords, whether major or minor, require no figures, though formerly tiler were marked with one or both of the figures 5/8. A key is minor when the third is at the distance of three semi- i tones from the tonic, and major when at four. The order in which the sounds are built upon the bass note is at the taste of the performer, that is, whether the third shall come next to the Mule, be placed in the middle, or be uppermost, thus:

Whenever the bass note steps out of its place into that of the third of the key, this change is called the first derivative

When a sharp precedes or follows a figure, it signifies at the note which that figure represents, must be sharped. Another made of indicating the sharp, sometimes used, is by a stroke or dash drawn through the figure.

Another set of combinations, called Discords, are procured from the Chord of the Dominant Seventh, termed the CHORD OF THE SEVENTH. (See above.)

When the bass steps into the place of the third, as before mentioned, it is termed the first derivative of the seventh, and takes the figures being the chord of sixth and fifth.

When the bass steps to the fifth, or dominant, it is termed the second derivative of the seventh, and takes the figures 4/3,

being the chord of the fourth and third. When the bass steps still a degree farther into the place of the seventh, it is termed the third derivative of the seventh, and takes the figures

and is called the chord of the fourth and second, or simply the second.

Thus far the figures snow what harmony is built upon the bass ; and when the bass ascends from its foundation place into those of the derivatives, the harmony is then said to be inverted, as the key-note, which ought to be at the bottom, is then above the bass.

In considering the numerous chords still to be explained, as the figures become so very complex, it is doubtful whether they tend to simplify our notions further than pointing out the root or foundation note of the chord. The discord of the DIMINISHED SEVENTH, is produced by raising the bass note of the dominant seventh a semitone, which forms a compound of three minor thirds,

and having the same derivatives as the dominant seventh. The effects of this chord in modulation are strikingly powerful; and it readily admits of a transition to any chord in which one of its notes may form a part. There is still a higher class of discords to be mentioned, which are produced by placing the chord of the dominant seventh upon the cent-(non chord of the tonic, forming the chord of the eleventh, resolving inn the common chord, thus

These discords are in fact a compound of appoggiatura notes, forming suspended harmonies, which ultimately melt into the common chord.

The following examples, with the chords filled up at length in notes, will be found simple and useful Persons, who have not the advantage of a master. will find themselves much assisted in their progress, by first writing out the figured basses and the top note., of each chord as here given, and then. without looking at examples, supplying the remaining notes according to their own ideas. After which. a comparison of their performance with the corresponding examples in this key, will enable them to correct any errors into which they may have fallen.


 * * * Here the fifth is understood to be sharp, to avoid the inharmonious interval which cannot belong to a consonant chord.

EXERCISE ON THE COMMON CHORD AND ITS TWO INVERSIONS, THE 6/3 AND 6/4.


 * In thorough-bass, the major third, as F sharp, may occasionally descend to the fifth D, when the former is not the upper note of the chord.