13. String Quartet in A major, KV.464
Few works so clearly demonstrate Mozart's genius for manipulating both harmonic and metrical rhythm. It also demonstrates his genius for variation, particularly in the Andante, here the third movement of the quartet. This is also a rather dense and complicated work in which Mozart draws not only on varying the theme, contrasting dynamics, contrasting texture, harmonic modulation, and variation of the meter (within the flexible 3/4 time) but all of these features and all in the opening Allegro. It has become trite to say a piece rewards repeated study and listening, but this quartet most certainly does.
While only the andante is in variation form the whole quartet is a journey of variations, the outer sonata-form movements in particular sharing a symmetry. In the opening Allegro Mozart begins imitative procedures on the main theme in the tonic (E) minor as soon as sixteen bars into the movement, development we would not expect in the exposition. At the near end of the exposition we see each instrument effectively in its own time before, in the development, we begin a new contrapuntal exploration. The last movement too, Allegro non troppo, is an exploration of a theme. It begins in dazzling imitation but at m.113 pauses and begins, piano, a tender and somber theme, an exploration which will run through all of Fux's species of counterpoint.
It is impossible not to mention the Andante to this work, which Beethoven saw fit to copy out (possibly along with the finale) yet I don't want to yank it apart for study. The unfolding of the variations is so extraordinarily transporting I will just leave you with Abert's words, that rather than mere theme and variation, we have a "dreamily wistful transfiguration." [Abert, 858.]
14-15. Duo for Violin and Viola in G, KV.423 & Piano Trio in G, KV.496 - Andante
We group these two works together on account of their light and Rococo nature enlivened by the wealth of variety of technique Mozart imbues in them. Mozart's craftsmanship is visible in works like these also, not just in the monumental works. Here we have contrapuntal treatment of light and even slight themes.
Duo for Violin and Viola in G, KV.423
16. String Quartet in D major, 'Hoffmeister,' KV.499
This quartet too tends to get rather slighted, falling as it does between the sets of the "Haydn" quartets and the final set of three quartets KV. 575, 589, and 590. We see here as in the A major quartet KV.464 contrapuntal and often canonic treatment of the main theme amidst development. Alec Hyatt King hinted at the peculiar mood of this piece, pervasive through the movements: is it wry humor or veiled sadness?
17. Ein Musikalischer Spass in F, KV.522 - Presto
Here is one of Mozart's most humorous statements in this "musical joke." Scored for strings and horns it is a symphony of sorts, sometimes classified as a divertimento. The piece is splendid piece of humor poking fun at a would-be composer, perhaps someone in particular. It is also a sort of contrasting companion to the contemporaneous Serenade Eine kleine Nachtmusic, KV.525. This joke is in four movements, all of which are filled with a variety of mistakes of the sort a bumbling composer trying to write a popular piece might make. In the final movement this "poor composer" twice attempts fugato and both times fails, the structure falling apart after a few bars. Who can repress a smile when the horns bumble in with their jocular them in place of a contrapuntal development?
We must make a special note about the following two pieces, which are not only among Mozart's greatest works but among music's greatest, though they are not quite as famous as the final symphonic trilogy, the operas, and others of great popular esteem. They are also among Mozart's biggest structures, the first movement of the quintet at over 350 bars (over 1,100 total) and the first movement of the concerto at over 400. As such, and also consistent with our survey, we will but lightly be touching upon these works and while Girdlestone in his (and the) classic work on the concertos discusses KV.503 at length and Rosen in "The Classical Style" does the same for the quintet KV.515, study of these works is far from exhausted.
18. Piano Concerto No. 25 in C major, KV.503 - Allegro maestoso
Part I | Part II
Years ago I attended a summer concert at which this concerto was performed. After the performance, during the intermission, a woman in the row behind me began to speak about the concerto, referring to it quite casually as "concert" music, i.e. "just concert music." You know, that pleasant-sounding but vapid sort of filler. Quite unlike the Beethoven which was to follow, of course. To this day I cannot account for the comment, I really cannot. You see, it is of course possible to be unaware of the structure of a piece. One can simply follow it and take in what one can, perhaps even drifting away here and there. Yet there is, of course, ingenious structure in Beethoven too. My best guess is this poor women simply saw the Beethoven as "serious" and the Mozart as "pretty." Aside from the crudeness of such categories and the injustice it does composers to lump them into genres and styles, the statement reveals a particularly lamentable view both of life and of Mozart in particular. In his essay on the G minor symphony KV.550 Tovey quoted the English poet Edward Fitzgerald who wrote in the 19th century that "People will not believe that Mozart can be powerful, because he is so beautiful."
So let Mozart and this magnificent concerto, with its ingenious conception and painstaking working-out, with its soaring majesty, its vigor and its tenderness, its lyric songfulness here and marching there, teach us that to be beautiful and joyous is not to be weak or shallow. Far from it. Indeed this concerto is the life-affirming and life-exalting counterpart to its cataclysmic predecessor in C minor.
Both Hutchings and Rosen noted the great economy of color that is one of this concerto's hallmarks. Specifically here we see a great economy of color, contrasting between major and minor. We will also see the orchestra to be the predominant force of this concerto and its prelude is a masterpiece in itself.
We begin with a clear and bold tutti forte, with the tonic harmony contrasted with the dominant. The grand opening is immediately contrasted by the bassoons and oboes, which in turn offer a gentle little phrase. It is as if we have been thrust to great heights and the winds then keep us aloft. After another tutti outburst the bassoons and oboes repeat their work and trade the phrase an additional time. Now the violins trade a dotted triplet figure back and forth in imitation against a rising bass figure before a tutti forte outburst launches the violins into a sprinting ascending scale and their previous figure falls to the basses who now use it to punctuate the scales. They then trade again, the basses with the scales and the violins with the dotted figure. Now the first violins trade the figure against the rest of the orchestra and the tension builds until it overflows in descending scales in the violins. Only at last do a series of G major chords with the rhythm of three quavers followed by a crotchet arrive and slow us down.
It is important to repeat on of Girdlestone's points about this opening and piece overall: it is marked maestoso and not brillante. "The work is majestic, not festive; if it is taken too fast the majesty vanishes and breadth of line gives place to something skimped and curtailed." [Girdlestone, 422] Yet we cannot look here at this marvel in its entirety but cut to the height of the development section and ask pardon for doing so. Here is the climax wherein the figures of the subjects break up into different groups, delving into canon which then loosens into imitative passages. Charles Rosen describes this well:
The final triumph of the massive power of KV.503 is the second half of the development section which–in addition to the piano's figuration is in full six-part polyphony, with imitative writing almost strict enough to be called canonic, a tour de force of classical counterpoint comparable to the finale of the Jupiter symphony or the ball scene in Don Giovanni. [Rosen, 257]19. String Quintet in C, KV.515 - Allegro I
The contrapuntal heights in the development here serves as the climax of the movement as in the previous concerto. The addition of the viola to the string quartet gives Mozart more possibilities for grouping instruments and moving themes amongst parts and with that flexibility Mozart greatly expands the scale of this sonata-form structure. This expansion is that of the tonic section, in which he remains exceedingly long through ingenious turns of modulation.
The unprecedented majesty of this work comes from the long immobility and the firm tonic harmony, its lyric poignance from the chromatic alterations that made the proportions conceivable. . . If listeners measured their experiences by the clock, the development section of the C major Quintet would seem too short; but complexity and intensity are a more than adequate substitute for length. The development is one of Mozart's richest: the climax is a double canon in four voices with a free counterpoint in the fifth (second viola) and almost the whole development is in minor, making the return to C major grand and luminous. [Rosen, 272]
–Girdlestone, Cuthbert. Mozart and His Piano Concertos. Dover Publications, Inc. New York. 1964.
Rosen, Charles. The Classical Style. W. W. Norton and Company. New York. 1971.
 see Yudkin, Jeremy. Beethoven's "Mozart" Quartet. Journal of the American Musicological Society, Vol. 45, No. 1 (Spring, 1992), pp. 30-74
 Of course given the structural similarities between this concerto and Beethoven's practice, such a shallow comparison is even more foolish.