First things first: last week I invited you to find the hidden quotation of the ancient “Dies Irae” hymn in Saint Saens’ Danse Macabre.  If you found it (at 2:25 in this clip) congratulations on having a damn good ear (and probably not a little pertinacity).  As I mentioned, I’d known the Danse since childhood, and the “Dies Irae” since college (which has come to seem almost as long ago), before I recognized this quotation–and only when I read a mention of its existence and went hunting for it.  And even that hunt took a while–and no wonder, for the hymn is, to steal Yeats’ phrase, “changed utterly” by Saint Saens.

The thoroughgoingness of this transformation got me thinking about a comparably extreme and quite miraculous one.  You’ll probably recognize the theme in this clip as one of the most romantic in music. So iconic is this theme that it’s become detached in the popular imagination from the work in which it’s found: Rachmaninoff’s Variations on a Theme by [Nicolo] Paganini.   The theme on which Rachmaninoff’s is based is that of the 24th of Paganini’s “Caprices”–etudes, in effect–for solo violin. (Paganini was to 19th-century violinists what Franz Liszt was to 19th-century pianists: an incomparable and almost inconceivably popular superstar.) The 24th Caprice is itself a theme and variations; its brief theme–it seems to have barely begun before it’s over–runs from 0:09 to 0:24 in this clip.  What does–what could–this instantly unforgettable scrap of sprightliness have to do with Rachmaninoff’s soaringly rhapsodic creation? Well…take the opening gesture of the Caprice theme, change its meter, slow it down, put it into major instead of minor, and–here’s the clincher–invert it (i.e., turn its melodic shape upside down), and…voila. When it comes to profoundly recasting a bit of musical material, and having its new guise be as (very) immortal as its old one had been, Rachmaninoff’s transformation of Paganini’s theme is in a league of its own: a bit of magic that’s become so familiar to us we can be forgiven for failing to recognize–not to mention credit–its genius.