Notes and analysis on J.S.Bach’s fugue in C minor BWV847
3 part fugue
1. The subject (annotated in red) is first stated in the alto voice.
2. Soprano states the subject a fifth higher in the dominant. Alto states the first countersubject (blue) bb3-4.
3. Bass voice states the subject, countersubject 1 in soprano voice, introduction of countersubject 2 (green) in alto voice.
The subject and both countersubjects are stated several more times – see markings in the score.
In the first development episode bb5-6, the subject is partially stated but is transformed towards the end of the figure.
Highlighed in yellow in episode 2 – a string of sixteenth notes in the bass going from c1 down to Eb, bb9-10. This is then reversed in melodic inversion in the soprano voice in episode 3 in bb13-14, eb1 to c3.
Episode 4 – use of a rising sequence with the rhythmic motif of the subject stated at first in the bass and harmonised a compound third higher in the soprano voice (circled), and completed in the bass, then the alto.
Episode 5 – Canon between soprano and alto (5th lower) followed by another rising sequence in bar 25-26.
Piece ends in a ‘tierce de picardie’ – C major.
References:
http://bach.nau.edu/clavier/nature/fugues/Fugue02.html
Jim Mennell Music 