d phrase ends with a
semicadence,--therefore the sentence remains unbroken; phrase three is
_exactly_ like the first, and is therefore an Antecedent, as before;
phrase four bears close resemblance to the second one, but differs at
the end, on account of the perfect cadence. The evidences of Unity and
Variety are easily detected. The main points are, that the second pair
of phrases balances the first pair, and that the two periods are
connected (not _separate_ periods). See also Ex. 53, first 16 measures.

LESSON 8.--Analyze the following examples. They are not classified;
therefore the student must himself determine to which of the above
three species of enlargement each belongs:

Mendelssohn, Songs Without Words, No. 29, measures 1-21, (first 4
measures an introductory phrase).

No. 37, first 17 measures.

No. 30, first 15 measures (last phrase irregular).

No. 16, measures 4-9 (small phrases).

No. 33, first 12 measures.

No. 27, first 20 measures (introductory phrase).

No. 3, first 29 measures, to double-bar (introductory phrase).

No. 36, first 27 measures (the similarity between phrase one and phrase
three proves the double-period form; the extra phrases are extension by
"addition," as in the group form).

No. 6, measures 8-17.

Mozart, pianoforte sonata. No. 13 (Peters edition), first 16 measures.

Sonata No. 2, first 16 measures (last four measures are extension).

Sonata No. 3, last movement, first 16 measures.

Sonata No. 10, second movement, first 16 measures.

Beethoven, pianoforte sonatas; op. 49, No. 2, first 12 measures.

Op. 10, No. 3, first 16 measures.

Op. 10, No. 2, first 12 measures.

Op. 26, first 16 measures.

Op. 31, No. 2, last movement, first 31 measures (extension by
repetition).

Schumann, op. 68, Nos. 16, 20, 33, first 16 measures of each; No. 13,
first 10 measures; No. 15, first 16 measures.

CHAPTER IX. THE TWO-PART SONG-FORM.

THE SONG-FORM OR THE PART-FORM.--Almost every musical composition of
average (brief) dimensions, if designed with the serious purpose of
imparting a clear formal impression, will admit of division into either
two or three fairly distinct sections, or Parts, of approximately equal
length. The distinctness with which the points of separation are
marked, and the degree of independence of each of these two or three
larger sections, are determined almost entirely by the length of the
whole. And whether there be two or three suc