G. Henle Verlag Piano Sonata No. 29 in B-flat Major, Op. 106 (Hammerklavier) Henle Music Folios Series Softcover

"Beethoven allegedly told his publisher Artaria, in connection with this Sonata, that Here you have a sonata that will be a hard nut to crack. Indeed, the enormous dimensions of the work, which was sketched in 1817 and completed in late 1818 or early 1819 and has nearly 1,200 measures, together with its numerous musical and technical challenges, long made it seem unplayable, and even today it is still considered a major challenge for concert pianists. The piece owes its nickname to the title of the original German edition, Grosse Sonate fur das Hammer-Klavier, since Beethoven had been wanting since 1817 to Germanize the term pianoforte for the printing of his piano sonatas."