Last week we saw Beethoven happening into jazz (and moving on to other things with nary a backward–or should that be forward?–glance).

After writing that post, it occurred to me that Mozart can be caught in the same act, though in Mozart’s case it’s not jazz in general he predicts, but a particular song. And for the life of me, I can’t remember what the song is.¬† Can you help?

In the finale of his last string quartet, K.590, he plays every which way with a little 3-note scrap of descending scale (it comes in right away at the beginning of the movement, which starts at 19:04 in this clip). The contrapuntal complications he works upon this fragment would take a while to recount (and a lifetime to properly admire) but I’m going to skip over all that and take you right to the little “closing” theme that ends the movement’s first section (it comes in at 20:55 in the clip). If it makes you laugh out loud, you’re forgiven: the syncopated, dizzying repetitions of the three-note figure instantly whisk us ahead a hundred years-plus to an age when ragtime roamed the earth. (The bluesy alternation of major and minor beneath the repeated figure is a demonstration of prescience squared). Mozart himself knew he’d hit on a remarkable, and remarkably winning thing, as shown by the fact that he works the repeated figure non-stop for almost the entire¬† “development” section–all the way to the movement’s “recapitulation” (which begins at 21:50).

What IS the raggy song Mozart presages here? Until someone is kind enough to tell me via a comment to this post, I won’t be getting nearly as much sleep as I should.