Concerning harmony, there is one chord only—all other harmonies are passing notes, inversions, prolongations, suspensions or retardations of chord-tones, or from sharped and diminished intervals. Harmony is a connection of different melodies. Before chords were known, they descanted, that is, they tried to sing to a melody, commonly a sacred hymn, called cantus firmus, different harmonical tones, and named this part, Descant; Italian, soprano; French, Le dessus. Later there was added to the tenor (which performed the cantus firmus) a higher part, named alto, and lastly, a lower part was added called bass. These four parts, though each melodious and independent in itself, harmonized closely with each other, all striving for the same aim.
Even to-day we must necessarily call such music good, wherein every voice acts independently of all others, and still in harmony with the same, in order to express the reigning feeling, and sustain the various shades in contrast to non-acting and lifeless trabants, which may be strikingly seen in many compositions, particularly in four-part songs for male voices, by Abt, Gumbert, Kücken, etc., wherein three voices (Brummstimmen) accompany the fourth with a growling sound escaping their closed lips.
The two cadences or musical phrases are the cadence on the tonic and the cadence on the dominant. The cadence on the tonic, consisting of the chord in the dominant, followed by that of the tonic, concludes the sense of the musical phrase, and is called “perfect” when the tonic is in the highest and lowest part. It corresponds to a period in language. The cadence on the dominant consists of the tonic, or the chord of the second or fourth going to the dominant. The cadence of the dominant suspends the sense of the musical phrase without concluding it. This is likewise the case with the cadence on the tonic, if the tonic is not in the highest and lowest part.
Q. You say nothing of the great mistake wherein two fifths or octaves follow each other?
A. Of course, the true nature of the proper arrangement of parts excludes all direct fifths.
It is considered by the new school “an exploded idea.” Mozart himself made use of fifths in the first finale of Don Giovanni.
Q. I have heard something of these fifths, but was told it was “irony,” being contained in the minuet which Mozart composed for “country musicians”?
A. You also find octaves in S. Bach’s “Matthew Passion,” p. 25, “On the cross,” where surely no ironical meaning was intended.
Q. Do you not say anything in regard to form?
A. Form is an “exploded idea” also. The composers of the new school construct their vocal music so as to let the poem govern the music in relation to metre and form; in their instrumental compositions, the form is governed by phantasy.