During the summers at Nohant, particularly in the years 1839–43, Chopin found quiet, productive days during which he composed many works, including his Polonaise in A-flat major, Op. 53. Among the visitors to Nohant were Delacroix and the mezzo-soprano Pauline Viardot, whom Chopin had advised on piano technique and composition. Delacroix gives an account of staying at Nohant in a letter of 7 June 1842: