Page:Fugue by Ebenezer Prout.djvu/245

Chap. XII.] shows that it is not necessary actually to combine the fugue subjects with the choral. This fugue is a very fine specimen of its class, and it is no disparagement to Mendelssohn's genius that he has here preferred the freer style. It would have been very difficult (perhaps impossible for anyone except Bach, to whom nothing seems to have been impossible) to combine the choral with either of the themes he had selected for his fugue. He therefore wisely chose rather to write an effective composition than to attempt elaborate and difficult combinations, which, had he succeeded in effecting them, would probably have smelt strongly of the lamp. An over-display of technical cleverness is very likely to be dry.

433. Sometimes only the first line of a choral, instead of the whole, is selected for fugal treatment. A well-known example of this is Bach's organ fugue in E flat, known in England as the 'St. Ann's Fugue.' This is a double fugue of a somewhat unusual form, in three movements. The first is a simple fugue in five parts, the theme of which we quoted at § 102 (c), and which is the same as the first line of the hymn-tune, 'St. Ann's.' This movement ends with a full cadence in the tonic, introducing the second subject.

This second movement is in four parts only, without pedals. After a regular exposition, the new subject is treated by inversion, and then combined with the first subject, of which the rhythm is now altered, and which assumes the character of a canto fermo.

Subsequently the canto is also heard against the inversion of the second subject. A full close in C minor leads to the third movement, which, like the first, is in five parts. The theme will be seen at § 49 (c). We now have a third exposition, followed by combinations of the third subject with the canto fermo in various ways, of. which one will serve as a sample.