There have been a number of requests here lately for information on counterpoint, and I received a request yesterday for more detailed instructions/hints/pointers on fugue construction.
I thought it might be interesting to see whether I could provide a simplified, illustrated guide to the art of fugue writing as I understand it. There may be pedagogues here who know more about this subject than I do, and I welcome their input. I am simply hoping this will be helpful as a starting-off point for those interested in trying to understand the anatomy of a fugue and how it is constructed, along with a few examples of just some of the many advanced techniques one can employ in writing a fugue.
In looking for a subject that would be easy to hear in almost any texture, I chose an old French folk tune, Ah, vous dirais-je, maman. Mozart used it as a theme for a famous set of piano varations. Almost everyone here will recognise it, either from that source, or as the English nursery tune Twinkle, Twinkle Little Star , or as the classroom primer The Alphabet Song.
Once the subject was chosen, I spent Sunday evening throwing together a fugue on it, annotating the score as I progressed. The fugue isn't deathless great, but it does what I wanted it to do - demonstrate the basics of fugue writing.
A PDF score of the Fugue Lesson is attached, which once you see it should be self-explanatory. Also attached is a MIDI of the Fugue Lesson. I chose easily distinguishable instruments to serve as the "voices" of the fugue: Soprano - oboe; Alto - clarinet; Tenor - bassoon; Bass - 'cello. Listen along with the MIDI while examining the PDF score; you may want to print out the PDF and make notes. Also attached is a PDF with errata - problems I ran into and mistakes I made, which you might find helpful in avoiding similar pitfalls yourself.
If you have any questions, please post them here, and I (or another willing pedagogue) will answer. I sincerely hope this is helpful.
Fugue_Lesson.pdf
Fugue_Lesson___MIDI.MID