I know what a fugue is. I also have been reading up on the form of the fugue and how to write in counterpoint. I wrote a canon and I have written a sonatina using sonata form. So theoretically a fugue shouldn't be all that much harder to write, especially with the free counterpoint that makes up the majority of the fugue.
But I am having trouble starting the fugue. Here is what I have thought out so far:
Key: C minor
Basic harmony of the subject
Starting voice: Soprano
Widest interval without arpeggios: Octave
Tempo: Moderato(more specifically, M.M 110)
Time signature: 4/4(at least for now, I might change it later on)
Number of voices: 4
Order of entry: SATB
And I have this so far for the subject:
G, F, Eb, D, Eb, D, C, Bb, C, Rest
1, 2, 3 4, 1, +, 2, +, 3, +, 4
2 measures, that's it. I have heard that if you don't have a long enough subject, you won't have the implied harmony you want in a fugue exposition.
So I looked at diagrams of Bach's fugues to see what the length of the subject is. Turns out, it is usually at least 3 measures long for his WTC fugues. I don't know how long it is for his other fugues though such as the fugue section of Tocatta and Fugue in D minor. But there is only 1 fugue I know of that has a 2 measure long subject. That would be Fugue in C minor WTC book 1, a fugue I am currently leaning along with the prelude(which is full of 16th notes, the prelude is).
Also, I don't know what to do out of 4 possible answers for the subject. Here they are:
Real answer without any harmonic minor
Real answer with harmonic minor
Tonal answer without harmonic minor
Tonal answer with harmonic minor
I know the key will determine whether to use a real or tonal answer but I don't know how it does that. I will listen to more fugues by Bach to try to figure out how he develops his relatively short subject into a full fugue.
But will 2 measures be sufficient for a fugue subject or should I expand my subject to something more like 5 or 7 measures? I mean the longer the subject, the more I can develop the subject and thus the more episodes I can have in a fugue. But too long and you have something more along the lines of a sonata in fugue form.