On 21 December 1774, Leopold Mozart wrote to his wife from Munich specifying various preparations which would need to be made before their daughter Nannerl set out to join her father and brother for the first performance of La finta giardiniera, which ultimately took place on 13 January 1775 to great acclaim. Leopold refers in his letter to some of Wolfgang's sonatas which he wishes Nannerl to bring with her, along with some variations – K.I79 and K.I80 – and sonatas by [J. C] Bach, Paradisi and others. Perhaps these were the five sonatas, K.279–83, to which a sixth, K.284 (written for Baron Thaddeus von Dürnitz at Munich in February or March 1775), was subsequently added. The ‘Dürnitz’ Sonata is stylistically quite different from its companion pieces: it is rather longer; includes a Polonaise en Rondeau as its central movement; has an extended variation finale; is of a much higher order of technical difficulty than anything in K.279–83; and, most important, has a first movement conceived on an orchestral scale, probably reflecting the preferences of Baron von Dürnitz for a big sound comparable to the orchestral music with which he would have been familiar at the court of Karl Theodore, Elector Palatine, whose famous ‘Mannheim’ orchestra only relocated to that city from Munich in 1778.

Against this hypothesis must be set the appearance of the autograph manuscript which gives the impression of having been written in a single sweep, without the slight differences in handwriting that might be expected if it had been compiled, say, in two sittings a few months apart.