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 to its melancholy middle movement in f minor, is now also available as a practical and reasonable single edition, which has been taken from our edition of the complete Mozart sonatas.