[Illustration: Example 36. Fragment of Schubert.]
The first, second, and third of these cadences is made upon the tonic harmony, on the accent of each successive fourth measure. But they are only semicadences, as the melody (uppermost part) rests upon the Third of the chord, c, instead of the keynote; this substitution of c for a-flat is sufficient to frustrate the perfect cadence and diminish it to a transient interruption. The final cadence is perfect, however, because there the uppermost tone is the keynote. See also Ex. 21; and Ex. 17, No. 2, fourth measure (semicadence, with a instead of f as principal tone in upper part, and disguised by the continuation of rhythmic movement to the end of the cadence-measure). In Ex. 17, No. 1, the cadence is made with the tonic harmony of G minor, but with the Third (b-flat) at the top.
LOCATING THE CADENCES.—Next to the recognition and comparison of the different melodic sections of a composition (in a word, the melodic delineation of the whole), the most significant task in music analysis is the locating and classifying of the cadences. They are the angles of the design, so to speak; and have the same bearing upon the sense of the music as punctuation marks have in rhetoric. Intelligent and effective phrasing, adequate interpretation of the composer's purpose, is impossible without a distinct exposition of the cadences,—if not of the inferior points of interruption between motives, also.
The best general rule for locating cadences is, probably, to look for them in the right place, namely, in the fourth measure from the beginning of each phrase. The fairly regular operation of this rule has been verified in Lesson 4. But exceptions have also been seen (in Ex. 17), and many more are certain to be encountered, simply because the principle of Unity (exemplified by the prevalence of the four-measure standard) must interact with the principle of Variety (exemplified in all phrases of irregular extent).
Therefore, the more reliable method, as already stated, is to define the beginning of the following phrase,—for each successive beginning involves a foregone cadence, of course. No very definite directions can be given; experience, observation, careful study and comparison of the given illustrations, will in time surely enable the student to recognize the "signs" of a beginning,—such as the recurrence of some preceding principal member of the melody, or some such change in melodic or rhythmic character as indicates that a new phrase is being announced.
LESSON 5. Analyze, again, Schumann, Jugend Album (op. 68), No. 6, locating every cadence and defining its quality,—as perfect cadence or semicadence. Also Nos. 22, 24, 26, 28, 30, 33, 14, 15, 16, 3,—and others. As a curious illustration of the difficulty which may sometimes attend the analysis of phrases and cadences, the student may glance at No. 31 (Kriegslied, D major); a more baffling example will rarely be found, for the piece abounds in irregular phrase-dimensions, and cadences that are disguised to the verge of unrecognizability; the only fairly reliable clue the composer has given lies in the formation of the melodic members (the clue intimated in the explanatory text following Ex. 35).
Also Mendelssohn, Songs Without Words, No. 34 (first phrase six measures long); No. 40; No. 18.
Also Beethoven's pianoforte sonata, op. 22, third movement (Menuetto); op. 28, second movement (Andante).
Again the student is reminded that it is not only permissible, but wise and commendable, to pass by all confusing cases; without being careless or downright superficial, to observe a certain degree of prudent indifference at confusing points, trusting to that superior intelligence which he shall surely gain through wider experience.