The plan was to have blogged about Koshkin's 24 preludes and fugues by now, and I still mean to do that.
It's just that while I'm at it I wanted to revisit Igor Rekhin's 24 preludes and fugues and I had not until recently even heard of G(h)erman Dzhaparidze's set of 24 preludes and fugues. I mean to give those a listen now. I am also wanting to get to the Castelnuovo-Tedesco cycle of guitar duets, though truthfully I probably can't add anything to what's already been said about that charming cycle. Friedrich Zehm has a set of six preludes and fugues that I know of but haven't been able to hear yet. That's not even counting fugues as movements or stand-alone works by composers ranging from the obvious (Leo Brouwer), to the established (Gilbert Biberian, Atanas Ourkouzounov) to the less well-known (there's a cycle that I've heard was composed by Puget Sound area guitarist composer Philip (sic) Quackenbush that I haven't had a chance to hear yet, either.
All that is to say that somebody could write a full-blown monograph on the heretofore largely overlooked (though not completely ignored) legacy of fugal writing for solo guitar or guitar duet. There's not much I feel needs to be said about the history of arranging and transcribing Bach fugues for guitar. In fact my convictions as a guitarist composer tend to be that if you have the time to transcribe or arrange Bach for the guitar you should really think more about composing your own fugues for the instrument.
The plan is still to get around to blogging about cycles of fugues for the guitar but it's going to take some time.