I was inspired after discovering Shostakovich’s preludes and fugues to try and find some more fugues written by other composers, particularly some that I could get the sheet music for easily. In my search I came across this one by Chopin, which was a surprise to me as I am quite familiar with much of Chopin’s music but was completely unaware he had ever written a fugue.
You can listen to a recording and follow along with the score here. Ashkenazy plays it a little too fast for my liking, it feels like it should be slower and more intense to me. It has quite a dark mood, and is chromatic in places.
The subject is first stated in the left hand, in A minor. As is traditional in fugues, this is a solo line when first introduced. Then the right hand plays the subject on the dominant (E minor). The left hand now plays an accompaniment, which imitates the rhythm of the main subject and supplies key notes in the harmony. This same accompaniment to the subject is used throughout the piece (modified where necessary).
A short bridging section comes next which modulates briefly to C major, and then the subject is back again in A minor.
The subject is played 10 times in total (to my count!), in A minor, E minor and D minor. Some of these are not full repetitions of the entire subject, but just the first two or three bars. Stretto is used towards the end (bar 52), when the right hand starts the subject on the dominant just two bars into the left hand’s entry. Sometimes the subject is started before the end of a phrase in the accompanying voice (e.g. bar 38) which is a technique I particularly like.
At the end of the piece the subject is played in full by the left hand in A minor one last time, with a trill being held over the top. Then we can hear fragments of the subject appearing, and an inversion of part of the theme in the right hand in bar 67 before the piece finishes on an octave interval.