Exactly why Mozart is great
Here is a mini analysis of the ‘desire’ structures of the Mozart excerpt featured in my previous post:
Micro scale: The first bar contains a plain C minor chord. At the second bar in, we get an intruder, a seventh note [red] creeps into every chord. A seventh note is often used just before the end of a section or a whole piece. Like a suspension, it clashes pleasantly and drives up desire for its resolution at which point it normally drops down a single note [green] to slot into its place in the final chord. Here, the chord sequence is a ‘cycle of fifths’, which means that each chord does resolve to its rightful expected place; but while the seventh notes do drop as expected [green], this isn’t the end, because each new resolved chord interjects its own seventh which again needs to be resolved. There is a sense of anticipation, possibly frustration, as micro resolution is repeatedly deferred.
Mid-level scale: The section is in C minor. By the second beat of the second line, we’ve cycled through in search of the elusive resolution and have finally got to G major (with another seventh note) [blue]; this is the ‘fifth’ chord of C minor and therefore the chord that you’d expect to precede C minor, ending the section neatly. The reaching of G is already a semi-resolution that prepares the true resolution, that of ending back in C. However, here we are deferred again and our desire for C is frustrated as the music interrupts the neat anticipated end by taking us to Ab in the bass [pink].
We also become increasingly rhythmically tangled towards the end of this section; while we started with the neat, rounded and so-nearly-completely-satisfying cycle of fifths, the neat rhythmical pattern each bar has so far followed begins to break down; the rhythm becomes unstable with chords not managing to last 3 beats any more [green bracket] and chord duration starting to cross bar lines and bend perception of timing [blue bracket] (3 stresses [starred in red] x 2 occurring over two bars, instead of 2 stresses [starred in grey] x 3 over the same; this is a common figure called a hemiola).
We have further deferral at the end with the pussy-footing around the G chord [starting at the orange arrow], building up additional desire for the C minor resolution – but on the next page we end up in a completely unexpected major key.
Macro scale: This snippet doesn’t give a sense of the macro scale of the whole piece, but the deferral of the mid-level resolution launches a whole new section that lengthens the piece and also propels it towards the ultimate macro resolution that is the end of the piece in its initial key (not C minor, where we are now).
The whole piece is worth a listen – our excerpt starts at 3.16. The last movement is my favourite and starts at 11.56. You’re welcome!