Bach: WTC I, Prelude and Fugue in C# minor

So far Bach has just been getting warmed up by tossing off a few simple and quite short preludes and fugues. Now, with the C# minor prelude and fugue he starts to show off what he can really do. Both of these pieces have rather an antique feel to them which reminds us that Bach comes from a family with deep roots in the world of music. Members of his family were church organists in Germany since the 16th century. The prelude almost has the feel of Renaissance counterpoint with the simple theme echoing itself at the octave then wandering off into free melodic counterpoint.

Let's just review what we have seen Bach do with the fugue so far:

• the fugue in C major was an exercise in stretto where Bach jams in twenty-four statements of the subject in a fugue only twenty-seven measures long. There are no episodes and only two measures of transitional material.
• the fugue in C minor has no strettos whatsoever, but lots of episodes as well as false entries, hidden entries and invertible counterpoint.
• the fugue in C# major is all about developing the motivic material of the subject and nothing else and has a minimum of statements of the subject.

This fugue, by way of contrast, has nothing but the subject and halfway through Bach adds a second contrasting subject (not a countersubject) and from then on there is even less room for anything but those two subjects heard against one another and against themselves in stretto. One huge difference from the C major fugue is that that subject was fourteen notes long, but this one only has four notes.

The subject has a venerable ancestry as it can be found in counterpoint going back centuries. Imagine if you were asked to write a long, long fugue with only four notes. And not only make it interesting, make it truly great. That is what Bach has done. I don't have to go over the details as some wonderful person has put up a clip of the piece with all the entries of both subjects shown in red, blue and pink (for when the subjects overlap a lot). Here is the clip: