Invertible Counterpoint in Bach's G Minor Fugue from Book II of the WTC (BWV 885)

by José Rodríguez Alvira

Bach's BWV 885 fugue offers excellent examples of invertible counterpoint. The subject (S) of fugue BWV 885 is presented by the tenor:

In measure 5 the tonal answer (A) appears in the alto while the tenor plays the countersubject (CS):

This countersuject will have an important role in this fugue. Not only it will appear each time a subject or answer is presented, but it will also be used in episodes and offer numerous examples of inverted counterpoint at the 8^th, 10^th, 12^th and the 13^th with the subject.

The soprano presents the second subject (S) in measure 9 while the alto plays the countersubject (CS):

In measure 13 the bass presents the answer (A) while the countersubject inverted at the 8^th appears in the soprano: