Friday, May 06, 2005

Let's Look For Sonata Form in Bach, the Way People Look for Jesus in the Old Testament

This is, mercifully, the last of the entries from the Well-Tempered Clavier in "Mostly Short Pieces" (although not quite the end of Bach, unfortunately). It's hard to put my finger on the exact reason, but analyzing Bach is a real grind for me. I think it's his heavy reliance on diminished sonorities as a means of making quick and dirty tonicizations and modulations- those are a pain when you're working from chord to chord with a pencil. You progress nicely until you hit a thicket of chormaticism, at which point you have to skip ahead until you find the next cadence point and then work backwards to see how the music winds up there. And, of course, this isn't a very accurate reflection of how the harmony functions, since when you hear these weird sonorities your ear has no idea where they're going to go. It's not like, when you first hear that diminished chord, you know that it's a diminished vii/IV. But, let's get on with it:

J. S. BACH "Well-Tempered Clavier, Book II (1748): PRELUDE in F Minor"

DeVoto's preface notes make out that the rounded binary form of this prelude should be appreciated as a prefiguring of sonata form: "One can sense that a distinct and mature sonata form was not far down the historical road, even though Bach himself did not live to see it." That sentence seems pretty loaded to me, implying that a mature sonata form is a thing to be greatly desired. Poor Bach, having to content himself with all those innovative preludes and concerti and arias and fugues when he could have been writing mature sonatas, right? He's like John the Baptist or something.

It really is an interesting prelude though, mainly because at first it seems so abstract. It starts with a stately little theme - very simple - based on a bass that moves by quarter notes and a melody (if it can be called that) based on a simple appogiatura-type suspension figure. The rhythm is like this- BUM dut dut dut BUM dut dut dut. It's in 2/4, so the second 'dut' of the 'dut dut dut' is the first eighth of a measure (we started on an upbeat). This second 'dut' is always a suspension from the harmony of the last measure, which then resolves on the last 'dut.' After four bars of this, we get the second 'theme' (even more simple) which is essentially Alberti-type arpeggiation, but without any melody. This is, then, just moving sixteenth notes- it contrasts well with the first theme for this reason.

The piece starts in F Minor (four flats) and plays through a section of Theme 1 and Theme 2. Theme 1 starts again, but now modulates to A-flat Major (the relative major), in whcih key it continues through the rest of this second iteration of Theme 1 and then another batch of Theme 2. So, 1 2 1 2 so far. Then - and here comes the interesting part - we get a sort of third texture which is like a composite of the first two. In this new texture, the bass has two voices, and moves in offset (by which I mean they syncopate with each other) quarter notes while the soprano arpeggiates chords in sixteenth notes. These arpeggios are, at first, conventional upwards-or-downwards but then break up into the Alberti-style figures. All this leads to a cadence in A-flat major. This whole opening section (which I'll call, creatively, the A section) repeats.

Have I glossed over anything of pecuiliar interest in this opening? Not too much. The progressions are pretty straight for most of it - i V7 i ii6 vii/V iv ii7/V V i sort of stuff (which is to say that there are a lot of diminished, secondary-whatever and dominant sonorities, but that's not a real surprise coming from Bach). The only moment I marked with an exclamation point (as is my habit when I encounter something that's unexpected and unprepared) is a sudden shift from A-flat major to A-flat (parallel) minor in measure 26. For just that one bar, we get: iv i. Bach almost immediately returns to A-flat major, but it's a strange thing to happen. I guess he felt there needed to be something surprising and uncertain right before the end of the section so that it wouldn't feel too settled. The other odd thing is the presence of what sound like 9th chords- a ii9, IV9, and I9. Now, the way the counterpoint works out, the 9ths of these chords could be written off theoretically as passing tones or other ornamental non-chord tones. Melodically, though, they sound like 9th chords. These make the overall harmony feel a little unstable and jazzy at times.

The B section is going to be hard to describe for the reasons I outlined at the top of this post- lots of diminished sonorities and fast modulations. Theory language is still poor for describing intensely chromatic music, especially in the case of Bach, whose harmonies are supposed to be so orthodox.

It starts with an iteration of Theme 1, in A-flat major, which rapidly undergoes a certain of chromatic alterations by means of accidentals. This leads to a (partially) syncopated two-voiced melody in the right hand (like the earlier two-voiced syncopated bass line) while the bass plays a figure derived from the Alberti stuff. There are lots of secondary dominants and secondary leading-tone diminished chords which bring us to E-flat minor, then B-flat minor, then A-flat major again, then D-flat major and then - with an alarming barely-prepared V7 dominant - to F minor. I could go through these 13 or so bars in excruciating detail, noting which vii/V7 has a non-chord-tone-6th or whatever, but it would be missing most of the point, which is that this is a highly chromatic section based on recombining the material from Theme 1 and Theme 2 into new figurations and then using those new figures in sequences which, in turn, mutate and break apart and so forth.

In fact, writing this, I note what a lot of bullshit most theory writing is (this is my barely-concealed hobby-horse for this post). Paragraphs like the last one are mind-numbing, even though I'm struggling to talk about the piece in as plain a language as possible. There's so much inherent ambiguity in some of these chords, particular with their dissonant 'non-chord tones', that naming a lot of them comes down to personal interpretation. I wonder if someone could write a computer program that would go through these sonorities and assign a probability to them - "%60 likely to be perceived as a predominant, %20 as tonicization of a surprising passing chord heard two measures ago, %20 as anachronistic Debussy-type chromaticism". And, really, that's the problem- all those are theoretically equally valid and language is ill-suited to spell out every possible ambiguity in a way that can even hope to convey the sensation to the reader. But back to this piece...

Bach then returns to a variation on the fused Theme 1/Theme 2 texture at the end of the A section, although the bass is now just a single voice moving in eighth notes instead of the offset two-voice line from before. He moves through progressions in F minor, momentarily tonicizing A-flat major in measure 63-64, and lets the piece draw to a close. There are a couple of unusual 9th chords once again- a III9 (which really amounts to a I9 in A-flat, in context) and a i9 (measure 66), but nothing too alarming.

And that wraps it up for the WTC, thank god.

Next post: More Bach, but easy. Think notebooks for young wives.


Post a Comment

<< Home