The Six Sonatas K. 279–284 were probably written around the beginning of 1775. Mozart refers to them in letters that he sent to his father from his trip to Paris (1777–79). In these letters he often refers to them as the “difficult sonatas” – probably alluding to the special interpretative demands.

He thus provided these works with rich dynamic and articulative markings, advising a reserved tempo for their performance. The Sonata K. 280, which has a special place amongst the early sonatas due...