The Piano Sonata op. 101 marks the transition to Beethoven’s late works. The composer’s increasing deafness was already manifesting itself in such a marked way that he no longer dared to appear publicly as apianist. In this sonata he experimented with unusual harmonies broke with form gave detailed German headings for the movements and for the first time also used a note so “unheard of” that it was not even on most ofthe contemporary pianos: the low counter E. The editors have undertaken a thorough revision of our edition and our catalogue now offers a single edition of this sonata.