Fugue 13 uses a 5-note repeated note pattern in its subject, Fugue 14 has a smoother subject with only 3 repeated notes and an expressive drop of a diminished seventh interval, the subject for Fugue 15 uses alternating high and low pitches that seem designed for two feet in the pedal, again quite distinctive, Fugue 16 is based on an agreeable little twisting melody, Fugue 17 is in two voices which are registered on separate divisions, Fugue 18 has a syncopation in it and alternates between a long and short beginning, Fugue 19 uses an upward chromatic pattern and there is a separate countersubject, though only 2 measures long, the subject of Fugue 20 suggests a basic harmonic pattern of I-V-I-IV-I, in cotrast, the 1-measure subject for Fugue 21 can be said to stay in the same key throughout, the first measure of the subject for Fugue 22 shares the same notes as that of Fugue 23, but repeated notes are used in the latter, which is also played on a fuller organ, since it is the last of this large set of fugues.