Bach Fugue in G Minor from WTC BK1 Analysis

In anticipation of the forthcoming assignment in part four of the course, I've decided to begin with researching the structure of a Bach fugue. I love listening to and playing fugues but I've only researched one in some depth before; that was for my previous OCA course 'From the Present to the Past'. In that exercise I analysed Bach's fugue in C minor from WTC book one, a piece I had previously played for a piano exam.

This time I am again analysing a piece I have played before (currently playing in fact, for another exam) - Bach's G minor fugue from WTC book one.

First of all, I needed to revisit the meanings of some words used when discussing fugues:

Fugue Terminology

Fugue - A composition based on canonic imitations. It seems as if one voice is answering or chasing another.

Subject - The main theme in the fugue. Initially stated in one voice, it is then imitated by the other voices.

Answer - The subject transposed by a fourth or a fifth. There are two varieties of answer - a real answer, in which the subject is transposed exactly, and a tonal answer where some intervals are modified for harmonic or tonal reasons.

Countersubject - This is material that accompanies the subject and answer. It is regularly used to be differentiated from free counterpoint.

Free Counterpoint - Material which is neither the subject, answer, nor countersubject.

Exposition - The first section of the fugue where each voice makes an appearance, presenting either the subject or the answer.

Stretto - This occurs when a subject or answer is played before the previous subject or answer has finished.

Episode - A section of the fugue where the subject does not appear in its entirety. Fragments of the subject and countersubject may be used in the counterpoint. Episodes are most often used to modulate and prepare the appearance of the subject in other keys.

Fugue Analysis

In order to carry out the analysis research, I printed a copy of the score from the petrucci music library, then wrote directly onto the score. Scanned images of the analysis can be found below:

 

References

The following pages were invaluable in providing the material for my research. This was not my own analysis, I simply researched the information found on these pages and made my own notes on the score above.

http://www.teoria.com/articulos/analysis/fugas/terminos.html

http://www.teoria.com/articulos/analysis/BWV861/

http://www.appstate.edu/~fankhauserg/fugue.html