[No.] 4 [Key] E minor [Description] 
The prelude begins with an eighth-note appoggiatura figuration phrased in pairs between a sustained cantus firmus in the bass and a lyrical melody in the soprano. There is a consistent legato/half-staccato phrasing throughout the prelude in which Shostakovich attempts to imitate Baroque period phrasing. Following the prelude, Shostakovich proceeds directly to the fugue without pause. The fugue is a double fugue in four voices with two distinct subjects developed in separate expositions. The first subject is a slow stepwise melody consisting mostly of half notes and quarter notes, while the second subject is a partial diminution or variation on the first subject (eighth notes instead of quarter notes). About two-thirds into the fugue, Shostakovich brings back the original subject in the bass combined with the second subject in the soprano. The E Minor Fugue is one of progressive complexity. The composition begins rather humbly with a quiet, conservative exposition, but it ends triumphantly with nearly every possible fugal device (invertible counterpoint, stretto, double stretto, diminution, augmentation, retrograde) exploited in the final bars.