50. There are still two points of importance to be considered in the selection of a fugue subject. First, it must be contrapuntal in character, or at least adapted for contrapuntal treatment. There are many beautiful melodies which would be utterly unsuitable for fugue; it is difficult to imagine fugues written, for example, on such subjects as the following—
Beethoven. Symphony in D.
Beethoven. Sonata, Op. 2, No. 1.
It is impossible to give any precise rules as to what constitutes a contrapuntal subject; but the student who has properly studied counterpoint will feel it instinctively. One probable reason why the melodies just given are unsuitable is that they are too much cut up by "middle cadences" (Counterpoint, §§ 480, 505). Sometimes a cadence is met with in the middle of a subject, as in example (c) of § 41; but in general the subject should flow continuously, as is the case in the large majority of examples already quoted.
51. Though not indispensable, it is often advisable that the subject itself should be adapted for stretto; that is, for imitation at less than the original distance (§ 16). This question will be fully dealt with later (Chapter VIII.).
52. The last point of importance to be mentioned is the necessity of distinct character in a fugue subject. A mere meaningless collection of notes, resembling a clumsy counterpoint exercise, will never make a good fugue. The chief essentials in this respect are a clearly defined melody, and a well-marked rhythm. Such examples as those we have given in § 28 (a) (b), § 34 (a), § 46 (a) (b) (c), illustrate the former; while in § 36 (a), § 41 (b), and § 46 (d) the melody and rhythm are of equal importance. As the invention of melody is impossible to teach, we must content ourselves with pointing out what is required, leaving it to the student's own imagination and skill to carry the principles here laid down into actual practice.
53. In analyzing a fugue, it is important to be able to determine exactly where the subject ends. In exceptional cases there may be a doubt about this; for instance, three different text-books give three different lengths for the subject of the C sharp major fugue in the second part of Bach's 'Wohltemperirtes Clavier.' In general, however, there is no difficulty. It has been already said (§ 42) that the subject should end with a cadence. If the subject begins with an accented note, the last note of the subject will usually (though not invariably) be that on which the answer enters. In other cases, the subject
