Regarding the third species of counterpoint by Fux, there is a task to analyze the two sample solutions given for two different examples of cantus firmus, comparing them with the rules and tips from page 25-26 in the course-book.
Both examples have their cantus firmus in the lower part. Here is the sample solution 1:
To begin with, I have marked all the intervals. In third species, there are now four notes against one in cantus, and to establish this pulse, the example opens with a rest. The intervals on the strong beats are all consonances, with opening and ending bars containing the usual octave, while the strong beats from the 2nd to the penultimate bar carry the preferred sonorities of 3rds (10ths) and 6ths. In this way, the consecutive fifths and octaves have been avoided. The dissonances are carefully controlled, approached and quitted by the step-wise motion, mostly as passing notes between consonances. I have to go back again to the dissonance rule I mentioned in Exercise 1.3, which has been given to me in the previous studies, in this case it concerns with the transition from 7th to 10th from bar 4 to bar 5, although by step in the upper voice, there is a jump in the lower voice. This is something I have been told by my teachers to avoid, but might have been their preference rather than the actual rule by Fux. The melody of counterpoint is very smooth, moving mostly step-by-step in wave-like motion, with minimal jumps, all to the consonant notes, and within the bar, rather than across the bar line, as favored by the advices. Also, the octaves that appear on the 3rd beat (downbeat, but slightly lighter than the first beat of the bar) are the only ones in the bar.
Next is the sample solution 2, with cantus firmus also in the lower voice:
Many things are similar as in the previous example. The rest at the beginning establishes the pulse of four notes against one, with the octaves closing and opening the counterpoint. As preferred, the sonorities of the 3rds (10ths) and 6ths occupy the strong beats from the 2nd until the penultimate bar, avoiding the consecutive fifths and octaves. The dissonances are all very carefully controlled, but these aren’t only the passing notes, as in the first solution, but there is also the nota cambiata in bar 2 and the double neighbor pattern in the penultimate bar, the new dissonances allowed for the third species. As such, the melody is slightly jumpier than in the previous example, however, the step-wise, smooth and flowy motion still dominate, and all the leaps are controlled within the bar, rather than across the barline.
Once again, it was very useful analyzing the sample solutions, since this type of exercise could serve not only for the better understanding of counterpoint, but also as an evaluative tool for my own solutions to practicing it. Lastly, there is no exercise for third species, but instead for the suspensions of the fourth species. Click here to see the Exercise 1.4.