Just because ...
The Prelude starts at 0:00. The Fugue starts at 01:47.
There a couple of noteworthy things about this piece that you can read along with in the score as you listen. The first is how beautifully idiomatic the writing is, particularly in the use of slurs, portamento and glissandi. This is not music that you can really replicate on a keyboard instrument to the same effect as having it on the guitar with the various hammer-ons, pull-offs, and the slidings up and down the strings.
The second thing that's significant is this is a two-voiced fugue. George Oldroyd and other scholars of fugue have highlighted again and again that there's no good reason to add extra voices to your fugal texture at the expense of good voice-leading practices.
Don't believe the theory teachers who tell you that if there are only two voices then it's a two-part invention rather than a fugue. The difference between a two-part invention and a fugue is generally explained by Kennan and Verrall and other specialists as being defined not by the two-voice texture but by at what pitch the second voice enters. If the second voice enters at the octave in canonic response to the first voice it's a two-part invention. If the second voice enters at the fifth then it should be regarded as a fugue. If the voice enters at any other interval and is strict we could think of it as a canon but for practical purposes an answer at the fifth shows that we're looking at a fugue and that's what happens here. Dzhaparidze has, of course, helped us a great deal by calling this fugue what it is!
If you want to hear more of the cycle go get the double CD release at the guitarist's website.
As with other projects I hope to blog through this beautiful cycle in the future but the Koshkin cycle is both partly recorded and the scores published so that took priority but that hardly means I've forgotten about this beautiful cycle.
I really, really wish a publisher would get behind this cycle and run with it! I could probably write an actual book-length project on fugal writing for solo guitar in the early twenty-first century if anyone thought there was the least bit demand for such a book.