39. Quite exceptionally an entire subject is to be found in the key of the subdominant—
Handel. 'Jephtha.'
The key of the piece is D minor; but this subject is decidedly in G minor, the B natural being, as its subsequent treatment shows, the chromatic major third of the minor key.
40. In addition to the modulations already spoken of, we frequently meet with incidental modulations in the course of a subject which ends, as it began, in the key of the tonic. Of these the most usual are to the subdominant key for a major subject, and to the relative major for a minor subject—
J. S. Bach. Cantata, "Wer Dank opfert."
Handel. 'Semele.'
Mendelssohn. 'St. Paul.'
In all these examples will be seen a short modulation to the key of the subdominant.
41. The same modulation is sometimes found with a subject in a minor key—
Handel. 'Messiah.'
More frequently, however, the incidental modulation for a minor key is, as said above, into the key of the relative major—
Bach. Organ Fugue in G minor.
Handel. Anthem, "In the Lord put I my trust."