| Fig. 91. |
In writing, use soprano, alto and tenor, or alto, tenor and bass; and do not separate upper parts more than an octave. For a chord or two they may (for the sake of better voice-leading) separate a tenth.
All hidden fifths and octaves are bad, except between I and V and V and I. [[Fig. 92a], b.]
[A] In severely strict counterpoint all parts above the lowest must be consonant with it. Dissonances, when entering simultaneously with it, must be treated as suspensions, and when used in the progression of a part from one chord to another, should be treated as passing-tones or embellishments. This excludes the use of the unprepared seventh and ninth; all diminished and augmented triads except in their first inversion; and all six-four chords, except when the lowest part is treated as a passing-tone.
The perfect fifth following the diminished fifth is good when taken in an upward direction stepwise in the higher parts. [[Fig. 92c].]
| Fig. 92. |
All cadences used in harmony are good.
Unless otherwise mentioned, put the cantus firmus in any part, but avoid its continued use in the same part.
EXERCISES
To canti firmi a and b write the first species in all parts. Write each three times, setting the cantus firmus in a different part in each solution. This necessitates transposing the cantus firmus, when setting it in the other parts.