Page:Fugue by Ebenezer Prout.djvu/27

Chap. II.]

At (a) the juxtaposition of the minor sixth and major seventh of the scale fixes the key at once. The same result is obtained at (b) by following the arpeggio of the dominant seventh by that of the tonic chord (Harmony, § 219). At (c) we are in doubt till the third bar, though we feel that the key is C, whether the mode will be major or minor; the A flat settles the question in favour of the latter.

32. In our next example

the key is fixed by the arpeggio of the tonic chord (compare example (b), § 30).

Here the interval of the diminished fifth followed by B flat shows the key to be G minor. In our last example

the first three quavers of the second bar fix the key.

33. Sometimes the subject, instead of being in the key of the tonic, is in that of the dominant throughout, as in the following instances—

That we have here the key of the dominant is shown, not only by the signature of the movement, but also (as will be seen in the next chapter) by the interval at which the answer replies.