A second point of resemblance is Chopin's habit of founding a whole paragraph either on a single phrase repeated in similar shapes, or on two phrases in alternation. By itself this practice is primitive almost to barbarism, and its employment in many of the Polish folk-songs is a serious depreciation of their artistic value. But when it is confined to an episodical passage, especially in a composition founded on a striking or important melody, it may serve as a very justifiable point of rest, a background of which the interest is purposely toned down to provide a more striking contrast with the central figure. Of its illegitimate use a noticeable example may be found in the 'Spring Song,' which, it must be remembered, Chopin never intended to publish: its true and right employment will be seen in many of the Mazurkas--such, for instance, as the first (in F sharp minor), the fifth (in B flat), and the thirty-seventh (in A flat), which is, perhaps, the most beautiful of all. In the longer works, which are the more varied in proportion to their greater scale, we should hardly expect to find examples of a mannerism which, by its very nature, stands at the opposite pole from variation: but its influence may be noticed in the short, clear-cut phrases and exact balance of such compositions as the Scherzo in C sharp minor. No doubt much of this exactitude is due to an intense desire for clearness and precision: yet none the less the particular way in which that desire is satisfied may be regarded as characteristic of the national manner. Beethoven does not attain the lucidity of his style by such close parallelism of phraseology.
Thirdly, Chopin was to some extent affected by the tonality of his native music. A large number of the Polish folk-songs are written, not in our modern scale, but in one or other of the ecclesiastical modes: notably the Lydian, which has its fourth note a semitone sharper, and the Dorian, which has its third and seventh notes a semitone flatter than the major scale of Western Europe. Some, again, end on what we should call dominant harmony; a clear survival of the ecclesiastical distinction between plagal and authentic. Of this tonal system, some positive traces may be found in the Mazurkas, the cadences of the thirteenth, seventeenth and twenty-fifth, the frequent use of a sharpened subdominant, and the like; while on the negative side it may perhaps account for Chopin's indifference to the requirements of key-relationship. Not only in his efforts at Sonata form does he show himself usually unable to hold together a complex scheme of keys, but in works of a more loose structure his choice seems to be regulated rather by hazard than by any preconceived plan. Sometimes, as in the end of the F major Ballade, he deliberately strays away from a logical conclusion;[42] sometimes, as in the sixth Nocturne, he forces himself back with a sudden and inartistic violence; more often he allows his modulations to carry him where they will, and is so intent on perfecting each phrase and each melody that he has no regard left to bestow on the general principles of construction. No doubt some of this weakness was due to defective training, some, also, to the prevailing spirit and temper of the Romantic movement. But, in Chopin's case, there was a special reason beyond. As a Pole, he approached our western key system from the outside, and although he learned its language with wonderful skill and facility, he never wholly assimilated himself to the method of thought which it implies.