pecies in one part only, may also be used.

[Illustration: 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.

[Illustration: Fig. 39.]

EXERCISES

Write two eight-measure phrases mixing the first and second species. [Fig.
39.]

To cantus firmus _a_ write one counterpoint above and one below, three
notes to the measure. [Fig. 31.]

To cantus firmus _b_ write one above and one below, in the second species.

CANTI FIRMI

[Illustration: Fig. 40.]

LESSON IV

THIRD SPECIES

[Illustration: Fig. 41.]

In this species, four notes are written in the counterpoint to each note
of the cantus firmus. The counterpoint may begin on the first, second, or
fourth quarter. The second quarter is, however, the most usual. [Fig. 42.]

[Illustration: Fig. 42.]

The exercises should begin and end with tonic harmony.

When the counterpoint begins on the first quarter it must form a perfect
consonance with the cantus firmus. When on the second or fourth quarter,
any consonance may be used.

All previous rules are to be regarded, unless exceptions are made.

At least one of the first three quarter-notes of a measure should be left
degreewise. [Fig. 43.]

[Illustration: Fig. 43.]

The last quarter of a measure is usually left degreewise. If approached by
a skip or by a degreewise progression of at least two quarter-notes, it may
be left by a skip in the opposite direction from which it was approached. A
skip of a third in the same direction is also good when this skip is
preceded by a skip of a third (_d_). [Fig. 44.]

[Illustration: Fig. 44.]

Parts may cross occasionally.

The use of non-harmonic tones, as in Fig. 45, is good in either part. At
_a_ the passing-tone, instead of progressing directly to the adjacent
chord-tone, skips a third to the other side of it and then returns. The
embellishment is treated in the same way, but is most effective when the
principal tone is the leading-tone, as at _b_. In both cases the
counterpoint should continue degreewise through the chord-tone. [Fig. 45.]

[Illustration: Fig. 45.]

The fifth, when in the lower part,