It may seem daring to compare Schönberg's piano works in their significance with Beethoven's. Compared with the immense number of 32 piano sonatas there are just six opera of Schönberg's which what is more, often are hardly longer than a few minutes. And still the compositional evolution of this great innovator of the music of our century is mirrored within these little piano pieces which, within the oeuvre of Schönberg, play a similarly important role as Beethoven's great sonatas ... — Reinhard Kager