Fig.34.



When writing second species in both parts no cantus firmus is used, both parts being original. One part begins on the first beat, the other may begin on either the first or second beat. [Fig. 35.]

Fig.35.


The interval formed by the two notes appearing on the second beat should be a consonance, or one of the following dissonances: The augmented fourth, the diminished fifth, the minor or diminished seventh when properly resolved, and the perfect fourth when approached in contrary motion.
All tones not belonging to the harmony implied on the first beat, must be treated as dissonances. [Fig. 36.]

Fig.36.


The seventh or ninth of the implied harmony of a measure, when approached in an upward direction, may be used in either part, provided it is consonant with the other part, or comes within the requirements of the exceptions. [Fig. 37.]

The passing major seventh and its root may appear on the weak beat, even when approached in similar motion as in Fig. 37a. The seventh must then be treated as a passing-tone.

Fig.37.


The cadences in Fig. 38 are good when writing second species in both parts. Those having the second species in one part only, may also be used.

Fig.38.

Writing the second species in both parts will, in this lesson, be confined to a mixture of the first and second species, as in Fig. 39.

In this do not use the second species more than four measures continuously in one part. It will be noticed that the second species may occasionally be used in both parts. In later lessons opportunity will be given to write it continuously in both parts.

Fig.39.