Fourteen years ago, the baritone Florian Boesch released a disc devoted to Schumann’s settings of the poet Heinrich Heine. It included the nine songs of the Op 24 Liederkreis, but omitted the best known of all Schumann’s cycles, the 16 songs to Heine texts that make up his Dichterliebe. Partnered as before by the ever meticulous Malcolm Martineau, Boesch has now remedied that omission with a new recording of that pinnacle of the German lied tradition.