Sonata-form (Part 10): Mozart's brilliant move

Tenth of a series of articles about sonata-form.

In my last installment, I was discussing two spectacular transitions from development to recapitulation, one from the first movement of Beethoven's Fourth Symphony and the other, the subject of this article, the last movement of Mozart's 41st ("Jupiter") Symphony. Specifically, I had been discussing the augmented sixth, the chord that can act as a sort of musical wormhole linking distantly related keys and which is the crux of these two passages, although in very different ways. (I'll return to the Beethoven Fourth next time.)

Here's the beginning of the movement, all very clearly in the tonic. The two musical ideas in this example— the little four-note fragment that begins the movement (and which would have screamed "counterpoint exercise" to Mozart's contemporaries) and what is really nothing more than a slightly embellished descending major scale"“ are the basis for the entire development section.

Much from little: the challenge Mozart set for himself

One of the tasks Mozart seems to have set for himself in this development was to see how many different keys he could cover in the least amount of time while using this minimal amount of material. At the very end of the development, Mozart uses an augmented sixth as a way of linking two crucial dominant seventh chords, thus bringing off one of the greatest magic tricks in all of music. The rabbit that Mozart pulls out of his hat is the tonic, the home key, in the form of that embellished major scale, restored to its original form.

Here are the details of how he does it.

It's important to reiterate here that you don't actually need to hear a tonic to know where it is, as this example demonstrates. That's the situation near the end of this development section: the music pauses on the dominant seventh of a key"“ a key using the minor scale, in fact— that never explicitly arrives. Here's that dominant seventh, followed by the tonic it implies.

In this context, here's what the note that will shortly be revealed as true tonic sounds like. It sure doesn't sound like home base, does it? In fact, in the world of the "wrong" key we're momentarily in, it's the sixth note of the minor scale and wants very strongly to fall into its lower neighbor.

The changing psychological effect

As a matter of fact, as unstable as the true tonic sounds here, there is a very simple way to bridge the gap to the true home key: simply follow the "wrong" dominant with the "right" one, and there you are! Note how completely the psychological effect of what is now the tonic has changed; it is still tightly bound to the note below it, but now, instead of wanting to move down to the fifth note of the old "false" minor scale, it's the tonic that makes the seventh note of the scale gravitate upwards. That's what a change of keys"“ a modulation"“ does: By introducing new notes into the scale, it redefines the psychological effect of every single note left over from the old key.

In any case, this juxtaposition of dominants is a perfectly plausible solution, just the sort of direct and concise move that Haydn and Beethoven loved to make— the musical equivalent of a two-handed chest pass. Mozart could have composed something like this.

Mixing Mozart and Beethoven (with a computer's help)

That was a pretty good try, and if I had a few more months, I'll bet I could make it sound perfect. What I've done is stolen the analogous moment from the first movement of Beethoven's Second Symphony and inserted it into the "Jupiter" Symphony. And, as a matter of fact, Beethoven ends his development with exactly that juxtaposition of dominant sevenths.

(To Maria Corley, my brother Robert and anyone else with absolute pitch who's familiar with the Beethoven Second: No, you're not losing it; I've transposed the Beethoven from D major to C major for the sake of consistency. I'm absolutely astonished that software exists that makes this possible.)

But Mozart didn't do straightforward very often. He was to the Classical style what Pete Maravich or Bob Cousy were to basketball; one could argue that he was the greatest show-off in music history. Here, after having dribbled through a minute of pyrotechnics that none of his contemporaries"“ not even Haydn"“ could have dreamed of approaching, Mozart makes the ultimate blind, behind-the-back pass to get back to the tonic.

That destructive chromatic scale

In order to understand how Mozart brings it off, we need to talk about the destructive properties of the chromatic scale.

I've mentioned the miraculous powers of the major scale many times in this series (especially in the fourth article) and marveled at the way this particular set of seven of the 12 pitches available in Western Europe's predominant musical system somehow makes one note in particular sound like a home base. Music that creates this sense of tonic is called tonal; music that uses only the notes of the scale is called diatonic.

What happens to this sense of home base if we play a scale consisting of all 12 pitches? Within this— the chromatic scale— all notes are equal and the sense of home base, or tonic, is destroyed. While purely diatonic combinations of pitches amplify the organizing power of the scale, combinations of notes from the chromatic scale can create tonal chaos.

Power tamed by Mozart

What we today call the Classical style"“ the music of Haydn, Mozart, and Beethoven"“ isn't primarily diatonic. Mozart especially, to reiterate the main point of a piece I wrote in January 2008, was besotted by the expressive power of chromaticism; his genius was to tame it and make it the servant of tonality"“ never more so than in the few seconds of music that end the development section of the "Jupiter" Symphony's finale.

The basic idea seems simple enough: Beneath the unfolding chord in the bassoons and horn, Mozart places a descending chromatic scale. No matter how many times I hear it, its effect is disorienting, like a momentary attack of vertigo. Listen to the resulting chords in very slow motion, and as you do, try to listen carefully to how the chromatically descending bass makes each resulting harmony a surprise.

Finally, we arrive at the next to the last chord in the sequence. What is it? It could be a dominant seventh, in which case it would behave like this. But it's not, of course. As that high note"“ the ears of the magician's rabbit, if you will— appears in the strings, the chord reveals itself as an augmented sixth "“ and we're home! Here's the whole passage one more time.

What Bobby Fischer did for chess….

On October 17th, 1956, in what is sometimes called "The Chess Game of the Century," the 13-year-old Bobby Fischer amazed the world with a Queen sacrifice and an ensuing 13-move checkmate combination against the grandmaster Donald Byrne. Even a very weak chess player like me can go through this combination and marvel at its clarity and inevitability. For me, the few measures of Mozart I've discussed here have the same brilliant and inevitable quality; and contemplating them gives me the same kind of pleasure as watching Fischer's moves unfold. To contemplate either Fischer's combination or Mozart's modulation is, in a way, to be present at the moments in time when they first appeared in the universe.

But when did Fischer's 13-move mate come into existence? Did he see it all at once? One imagines he must have, but there's no way of really knowing. And what about Mozart's insight that he could connect those two chords in the way he did? Perhaps he had the idea in his back pocket for weeks. But I like to think that he saw it at the last moment, like a quarterback finding a receiver in the corner of the end zone as time expires.






To read previous articles in this series, begin here.