|Book 1 - No. 1 - C major - Fugue|
Bach begins the Well-Tempered Clavier with a marvelous "beginner's" fugue. It has a clear, major, tuneful subject. And the entire fugue is constructed almost exclusively from this subject with very little additional material. Twenty-four subject entries distributed about four voices, sequenced and layered over time so that it seems the entire universe is woven from this simple, omnipresent thread. Was the number subject entries (exactly 24) intentional to match the number of keys and therefore the number of fugues in the first book of Well-Tempered Clavier? Many have noted this fact in this fugue referring to it as "programmatic". Bach is well known for what you might call his numerology: his frequent tendency to encode meaningful letters and numbers into the structure of his compositions. As a further illustration of Bach's thouroughness, Bruhn points out that the final note in the fugue was in fact the highest possible note on typical keyboards of Bach's time. The final note of the companion prelude was the lowest. (For another example of Bach's programmatic numerology, see the final fugue of the Well-Tempered Clavier, No. 24 in B-minor).
In the absense of additional fugal devices such as subject variation or countersubjects, Bach develops the narrative from the most natural tension available in a fugue: stretto. Stretto means that a subject enters in a new voice before the last voice has finished its own subject statement. Multiple subject entries overlap. This increases the tension and so the drama of the narrative. It unfolds like very natural growth; the narrative is maturation, as graceful and as welcome as a flower unfolding before your eyes. With stretto, the growth accelerates, highlighting the essential personality of the fugue: the subject. You can hear the subject entries falling into sections: first, the exposition with no stretto. The voices enter in pairs of call and response, another frequent design in fugue expositions. Then, the voices begin to enter in stretto. The stretto gets more and more intense, the texture more and more dense. There is a thrill in this escalating density, complexity, and community. Just the subject, the subject interlocking with and echoing itself, the subject piling on top of subject, tightly braided against itself, this simple, ominipresent thread.
A visual representation of this fugue vividly reveals the occurance and degree of stretto as well as the overall sectional organization of the fugue itself. It is clear that the very density of the subject entires alone saturate the musical space leaving little room for alternative independantly meaningful constructs (e.g. episodes, countersubjects, etc.). This fugue seems all the more worthy to begin the Well-Tempered Clavier for this reason: it is constructed of the most minimal means. As Altschuler says, "it's all about the subject". With only the subject, its dense overlays and virtually no constrasting material, it is a wonder how Bach manages to make this fugue clear. Altschuler provides some wonderful analysis with regard to this question. Among his observations is that the pair of quick 32nd notes in the middle of the subject serves as a kind of marker. They occur practically no where else. Whenever you hear that quick downward run, you are hearing a subject entry.
Bach wrote at least one other fugue dominated by stretto: Book 2: No. 5 in D-major.