Rules For Third Species of Strict Counterpoint in Two Parts.
In the Third Species, four notes of the C.P. are written to each note of the C.F.
I. Leaps in the C.P. must be avoided with even more care than in the Second Species.
II. The first note in the measure must be a Consonant; the second and fourth may be Passing Notes, or the third may be a Passing Note, provided the second and fourth are Consonant.
- Passing Note on second beat.
- Passing Notes on second and fourth beats.
- Passing Note on third beat.
- Passing Note on fourth beat.
It is also permissible to make the second and third beats dissonant, provided it is done as follows:
It should be used sparingly. The same figure in the C.P. should not be used twice in succession, if it is possible to avoid doing so: to avoid monotony. Thus the following passages are poor.
III. The Unison may be used provided it is not on the first beat in the measure
IV. A scale passage must never be included in the limits of the augmented fourth, thus:
If it ascends it must go one degree higher.
If it descends, one degree lower, thus:
No. 2 is still better if preceded by the degree above, thus:
Example. C.P. above.
The third species may also be written in three against one, or six against one. (To write these varieties, change the whole notes of the themes into dotted half-notes.)