Bach: WTC 1, Prelude and Fugue in B minor

As this is the last prelude and fugue pair in Book One, you might expect Bach to give us something special, and so he does. The prelude is in the form of a trio sonata movement with two contrapuntal voices over a running bass. There are two halves, each repeated. The prelude alone takes five or six minutes depending on the tempo. The upper voices are constantly imitating one another at fairly brief intervals but the counterpoint is rather free as the imitation is changing, not strict. For example, at the very beginning a canon at the half note is suggested, but it mutates after a couple of measures only to suggest a new canon a few measures later. This goes on for the whole prelude in various ways. Here are the beginnings of each half so you can see how it works:

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As you can see, the imitation disappears after a couple of measures. Same in the second half:

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But the most interesting things happen in the fugue which spans seventy-six measures and about ten minutes in duration--by far the longest fugue in the set. Here is the subject:

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This is a very notorious subject, of course, because it contains all twelve chromatic pitches making it famous for having anticipated the twelve-tone system of Arnold Schoenberg. Of course, the basic concept of serial music is that no pitches are repeated until all twelve have been heard and here, some notes, B and F# for example, are heard more than once. But if you spend much time examining the music of Schoenberg, such as the Violin Concerto, you will notice that he often does not follow that rule. This is certainly the most chromatic fugue subject that Bach ever wrote. Structurally, it is not so unusual, once you get used to how this very chromatic subject influences the harmony. The most unusual element is the false entry: several times Bach states just the first seven or eight notes of the subject and then drops it. The same curtailed entry often then appears in another voice before we hear the full subject. We hear more false entries in this fugue than I think we have previously. The other really interesting element is a lovely imitative sequence Bach uses in more than one episode:

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Every time that comes back it is more haunting.

Now let's hear two performances. First, Bob Van Asperen:

And second, Sviatoslav Richter (unfortunately, without the score):