It is quite possibly the most recognizable movement from Mozart's piano concertos. With its rolling triplet feel over the spring of gentle pizzicatos, the second movement of Mozart's Piano Concerto No. 21, K. 467 wafts along like a cloud drifting in a summer sky. Musicologist David Grayson calls the movement "a sonic dream world" and writes that "it offers moments of sublime beauty and ends in a state of bliss, but its surface serenity cannot conceal the turmoil that lies beneath."
In musical terms, that turmoil plays out in bold and unexpected harmonic shifts. To the ear, these shifts have the feel of that summer cloud obscuring the sun, shadows darkening what lies below. To the eye, these harmonic shifts appear on the page as added sharps and flats, notes that, as interlopers from other keys, show up where they're not expected and evocatively, even seductively, complicate the music's emotional landscape.
The dramatic harmonies in Mozart’s Andante were so alarming that one individual who saw the score early on may have thought they were errors. In a letter of Jan. 14, 1786 Mozart's father, Leopold Mozart, wrote reassuringly, "Indeed the new concerto is astonishingly difficult. But I very much doubt whether there are any mistakes, as the copyist has checked it. Several passages may not harmonise unless one hears all the instruments playing together. But of course it is quite possible that the copyist may have read a sharp for [a] flat in the score or something of the kind, for if so it cannot be right." (The Letters of Mozart and His Family, trans. Emily Anderson)
With its ineffable beauty and moments of yearning heartache, there isn't much that's "not right" with Mozart's Andante. But if any of this music is wrong I, for one, wouldn't want it to be right.
