The music of both composers is shot through with wit, but here too they differ. Haydn is not merely witty, he is funny, a prankster reveling in outright jokes. Take this, perhaps the most famous joke in all of music, from the second movement of his 94th symphony. It's almost slapstick: He lulls us into a trance; then, when we least expect it, he bashes us over the head. And here is a lesser-known example, a delightful quartet finale. Its opening notes sound just like an ending, a passage of apparently clinching finality, after which we are introduced to a little snippet of tune that seems stuck in its own narrow groove, unable to get anywhere. All of this is then repeated almost verbatim in another key, and then, within another bar or two, we suddenly realize that somehow, despite (or as a result of)all this nonactivity, we're actually off and running. These are high jinks of the very highest order.
Mozart is certainly capable of broad burlesque—his comic operas contain many examples—and he even wrote a piece chock-full of jokes both elevated and silly, unambiguously titled A Musical Joke (Ein Musikalischer Spass). But in general, his wit is of a different order, a quicksilver play of ideas, intellectual juggling of dazzling speed and deftness, more likely to make the listener smile in wonderment than laugh out loud. Take as a single example this easily overlooked little passage from the rondo of the 23rd piano concerto; it is, in its essence, nothing more than a functional bit of connective tissue taking us from one place to another within the movement's structure. Ten brief bars—about 10 seconds—of basic scalar material, doing its job efficiently and economically. But it is at the same time so richly and amusingly characterized, so full of piping energy, with its determined but struggling piano line climbing its stutteringly inexorable way up to the note E, punctuated along its course by deadpan commentary from the winds, sneaking in the D natural that signals the change of key with almost undetectable sleight of hand—the passage almost constitutes a miniature comic universe all by itself.
The final difference I'd like to discuss is the most difficult to demonstrate, but may ultimately be the most telling. Haydn is a great artist, and like most great artists, his emotional range is broad. But he is also the sanest and most balanced of composers, and his intentions are always clear, his procedures, regardless of how playful or original or ingenious, always limpid. Even this portrayal of Chaos, from the overture to The Creation, seems orderly. When his work expresses jollity, it's damned jolly; when it reflects anguish or perturbation (emotions much more characteristic of his early music than his later), it leaves you in no doubt about its distress.
Mozart is different, and to music lovers, the adjective Mozartian, while always suggestive of exquisite grace, also connotes an umbral, aural world where emotions shimmer with ambiguity and confront their own opposites. Listen to the slow introduction to the first movement of the D major string quintet. Is that opening cello arpeggio an assertion, or a question? Does the response of the four other strings offer consolation, or despair? Is the cello listening to the answer, or is it oblivious? Impossible to be sure. And listen to another slow introduction, the extraordinary opening of one of Mozart's other quartets dedicated to Haydn. What in the name of God is going on there? What are we to make of the painful, unresolved dissonances, the false relations and harmonic slide-slipping? Many early purchasers of this music believed it to be replete with printers' errors and returned it to the publisher for a refund. (When Haydn was asked what he thought of the passage, some years after Mozart's death, he said something along the line of, "If Mozart did it, it must be right.") And from a passage toward the end of the middle movement of the piano concerto whose rondo we discussed earlier, listen to these eerie few bars . Am I alone in hearing, amidst the prevailing ghostly disquiet, the spectral weirdness, a hint of derision, even disrespectful mirth, in the dialogue between the piano left hand and bassoon? And consider this evocation of rampant adolescent horniness from The Marriage of Figaro. Ardor, agitation, heedlessness, exhilaration, confusion, raging hormones: It's all there, and in an irresistible melody of melting beauty. I don't know of another composer who could manage all that, let alone manage it with such apparent effortlessness.
So, does all this imply Mozart was in some way a better composer than Haydn? I have two contradictory responses to that question. The first is: No, at altitudes as stratospheric as this, there is no such thing as better, there are only different ways of being great. The second answer, which I can't really defend, but which I suspect I share with a majority of music lovers, is: Yes, of course. Mozart stands alone.
But the answer may partly depend on what one is looking for. Some years ago, I was discussing music with two friends, one of them a distinguished contemporary composer. We were chewing over the following peculiar question, peculiar especially since it concerned an experience none of us had had in approximately three decades: If you had taken LSD and suddenly realized your trip was heading seriously south, what music would you put on the stereo to restore your emotional equilibrium and silence your demons? All three of us agreed without hesitation: a Haydn quartet. Almost any Haydn quartet.