At the first performances of this sonata, composed between 1920 and 1922, even close friends of the composer were perturbed: Following the intoxicating sounds of La Valse, the smaller scoring and modern musical language of the sonata were a shock. Yet this pioneering work has now become a permanent fixture on the concert stage. To help the players, there are two performance scores in which the other instrument’s part is also given. Both parts are included in a marked and an unmarked version. The world-renowned musicians Christian Poltéra and Frank Peter Zimmermann provided the fingerings.