intervals of time.

(4) The melodic contents of the first measure, or measures, are copied (more or less literally) in the next measure, or measures; and are encountered again and again in the later course of the piece, thus insuring a fairly uniform melodic impression from which the character and identity of the composition are derived. Turn to the 8th Song Without Words of Mendelssohn, and observe how insistently the figure

[Illustration: first fragment of 8th Song]

and its inversion

[Illustration: second fragment of 8th Song]

run through the whole number.

(5) The specific figure of the accompaniment is usually reproduced from measure to measure (or group to group) throughout whole sections of the piece. Observe, in the 37th Song Without Words, how constantly the ascending figure of six tones recurs in the lower part (left hand). Glance also at No. 30; No. 1; No. 25. Many other evidences of Unity are invariably present in good music, so naturally and self-evidently that they almost escape our notice. Some of these are left to the student's discernment; others will engage our joint attention in due time.

In every one of these manifestations of unity there lies the germ of the principle of Variety, which quickens into life with the action of the former, always following, as offspring and consequence of the primary unity. Thus:—

(1) The beats, though uniform in duration, differ from each other in force. The first pulse in each measure (or metric group of any size) is heavier, stronger, than the following. It—the first—is the "impulse," and is what is called the accent. This dynamic distinction it is that gives rise to the two fundamental classes of rhythm, the duple and triple. In duple rhythm the accent is followed by one unaccented or lighter beat, so that regular alternation of heavy and light pulses prevails incessantly. In triple rhythm the accent is followed by two lighter beats, creating similarly constant, but irregular alternation of heavy and light pulses.

[Illustration: Duple and Triple Rhythm]

This distinction is so significant and so striking, that the music lover who is eager to gain the first clues to the structural purpose of a composition, should endeavor to recognize which one of these two rhythmic species underlies the movement to which he is listening. It is fairly certain to be one or the other continuously. Of duple measure, the march and polka are familiar examples; of triple measure, the waltz and mazurka. The "regularity" of the former rhythm imparts a certain stability and squareness to the entire piece, while triple rhythm is more graceful and circular in effect.

(2) The same dynamic distinction applies also to whole measures, and

(3) to accents. The first of two successive measures, or of two or more accents, is always a trifle heavier than the other.

(4) The melodic contents of the first measure may be exactly reproduced in the succeeding measure; but if this is the case, they are very unlikely to appear still again in the next (third) measure, for that would exaggerate the condition of Unity and create the effect of monotony.

[Illustration: Example 1. Fragment of Folk-song.]

The measure marked b is exactly like a. But c is all the more contrasting, on account of this similarity.

Or, the melodic contents of a measure may be thus reproduced, as far as the rhythm and direction of the tones are concerned, but—for variety—they may be shifted to a higher or lower place upon the staff, or may be otherwise modified.

[Illustration: Example 2. Fragment of Beethoven.]

Compare the groups marked a and b, and observe how the principles of unity and variety are both active in these four measures, and how their effect is heightened by the formation of c.

(5) The figures of the accompaniment, though reproduced in uniform rhythmic values and melodic direction, undergo constant modifications in pitch and in shape, similar, to those shown in Ex. 2. See, again, No. 37 of the Songs Without Words and note the changes in the formation of the otherwise uniform six-tone groups.

LESSON 1.—The student is to study this chapter thoroughly, and write answers to the following questions; if possible, without reference to the text:—

1. What does Form in music mean?

2. Define the conditions which constitute good form.

3. When is a composition faulty in form?

4. What do discriminating listeners recognize in music?

5. What is the difference between the sounds of music and those of language?

6. How does this prove the necessity of form?

7. By what is the presence of form in music shown?

8. What is the beat?

9. What is the measure?

10. By what means are the measures indicated, (1) to the reader; (2) to the listener?

11. To what does the further multiplication of the beats give rise?

12. What are cadences?

13. What purpose do they serve in music?

14. What is the best general name for a melody?

15. What object does it fulfil in music form?

16. What are the two vital requisites upon which the enjoyment of an art creation depends?

17. What purpose does Unity serve?

18. What purpose does Variety serve?

19. What is the great problem of the art-creator?

20. Define the conditions that confirm the principle of unity in music.

21. Define the evidences of variety in music.

CHAPTER II. FUNDAMENTAL DETAILS.

TIME.—Time is the same thing in music that it is everywhere else in nature. It is what passes while a piece of music is being played, sung, or read. It is like the area of the surface upon which the musical structure is to be erected, and which is measured or divided into so many units for this, so many for that, so many for the other portion of the musical Form. Time is that quantity which admits of the necessary reduction to units (like the feet and inches of a yardstick), whereby a System of Measurement is established that shall determine the various lengths of the tones, define their rhythmic conditions, and govern the co-operation of several melodies sung or played together. Time is the canvas upon which the musical images are drawn—in melodic lines.

TEMPO.—This refers to the degree of motion. The musical picture is not constant, but panoramic; we never hear a piece of music all at once, but as a panorama of successive sounds. Tempo refers to the rate of speed with which the scroll passes before our minds. Thus we speak of rapid tempo (allegro, and the like), or slow tempo (adagio), and so forth.