For nearly two hundred years, scholars believed Mozart's Flute Concerto No. 2 in D major, K. 314 (K. 285d) was originally composed for the flute in Mannheim in early 1778. In 1952, musicologist Bernhard Paumgartner demonstrated conclusively that Mozart reworked the Oboe Concerto in C major, K. 271k, into a concerto for flute. Mozart composed the Oboe Concerto for Giuseppe Ferlendis, oboist in the orchestra of the Archbishop of Salzburg, sometime between the beginning of Ferlendis' service at the Salzburg court (April 1, 1777) and Mozart's departure for Mannheim (September 22, 1777). Mozart's father probably sent the manuscript of the Oboe Concerto to Mozart, when he apparently used the work in an attempt to get himself out of an embarrassing situation. According to Mozart, Ferdinand Dejean, a surgeon with the Dutch East India Co. whom Mozart had met in Mannheim, commissioned three flute concertos from the composer. Only one exists from this period, K. 313/285c. Most likely, Mozart revised the Salzburg Oboe Concerto to present to Dejean as a new flute concerto. Mozart never finished the third piece and the composer's fee was not fully paid. (Dejean also commissioned three flute quartets, only two of which Mozart finished.)
Mozart's Flute Concerto in D major, K. 314, is an honest reworking of the oboe piece, not merely a transposition from C major to D major. The composer's sensitivity to the differences between the flute and the oboe enabled him to produce a flute part so idiomatically composed that subsequent generations praised the work as an original flute concerto. The concerto is scored for an orchestra of two oboes, two horns and strings. The first movement is far more interesting than that of the G major concerto, K. 313. In K. 314, the orchestration is scored in a lighter, more transparent fashion, highlighting the soloist and giving the numerous recurrent rhythmic figures more presence, especially the falling passage in the orchestra that first introduces the solo flute. Mozart's central slow movement is elegiac, with the flute placed throughout in its most liquid range. Mozart once wrote that he despised the flute, but the elegance of this movement makes this difficult to believe. The ebullient, Haydnesque finale is a Rondo in a quick 2/4 meter, with a rondo-theme that is bouncy and jagged. Most notable is the beginning of the central episode in which a tune based on the rondo-theme is developed in three-part counterpoint.