...and even a few more words for Haydn's variations.
As I've mentioned, the compelling feature of these variations is not how they vary. Though the chromatic supporting lines may entrance us while we are reading the score as they may have motivated Haydn to put pen to paper, it is the tune that holds our attention. We adore this tune, as Haydn did, and wish it to change very little. (Could you imagine variations on Eldewiess?)
There is nothing in the tune to confuse the listener. For instance, the one chromatic pitch does not obscure the implied harmony but instead strengthens "Sol" as we prepare to leap to the high "Do" that brings us near the conclusion of the anthem. The ability of the tune to speak so meaningfully, to rely on your ear to understand a 'D' Major seventh chord, is the legacy of cruel Amaryllis
. And on this side of the Baroque, our music makes a shift from a primarily singing tradition to a primarily instrumental tradition.
It is, perhaps in part, the lure of weird chords that comes over one while looking at the five lines and four spaces that would encourage Haydn's students and the generations after them to continue the exploration confusing chromatic lines and clever acoustic devices. One could argue that a failure of contemporary classical music (there are as many failures as successes, at least) is the failure of educating listeners to learn the extended vocabulary offered by instrumental music. In other words, the frustration of Schoenberg's audiences wasn't because he couldn't write a good tune. It was because the unhappy listeners couldn't sing his kind of tune. And ultimately, always, music is an art of singing.