Hi,
sorry for the delay but I've been away on a short holiday the last couple of days. I did attempt to convey my thoughts through use of my rare telekinetic abilities, but my powers have a limited range!
I enjoyed the prelude very much. I thought it could have been a tad longer; perhaps could have repeated but with slight harmonic variations. The chords used were very nice and flowed together very well. Although a few of the progressions were slightly predictable you tend to 'colour' some of your chords which makes things a whole lot more interesting to me. The slight level of predictability is therefore forgiven

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The opening theme/motif is a good one and allows for lots of development. I heard the theme reoccur throughout, giving the piece some unity. At the beginning the harmonies work well, and I especially like the resulting augmented chord at 00:11.
I love the chord progression at 00:28-00:32. It's sort of a cycle of fifths (B, E then A I think!) and resolves itself beautifully onto a chord of Fsharp minor. The progression works well I think because it is a bit unexpected, and also because you do not use 'straight' chords save perhaps for the resolution. If you ever write any non-fugal pieces, I'd play around with this progression, or perhaps use it as a launching pad for new ideas. When I first heard it I expected you to go into a cycle of fiths and then some ascending fourths, similarly to a passage in the sourcerer's apprentice I believe!
At 0:45 I think it gets a little bit cluttered harmonically in comparison to earlier on. However, the following sequential passage sounds a lot better to my ears!
The restatement of the subject at the end of the piece works well, and helps add to the overall coherence of the structure.
What I enjoy about the fugue as a whole, is that although you have used some convential chords you also reach for some pretty unconvential ones that add intrigue to the piece. I did think there a very small number of places where the chords might have clashed a bit too much, but this is just based on my own opinions about harmony!
Although I'm not an expert of fugues in anyway I think it's very well done on the whole, but perhaps some of the harmonies were slightly too dissonant for this kind of music.