This set of performances has been in my CD collection for decades and I have loved them from the start. Since then I have added other fine performances by other respected world-class pianists but none of them have surpassed Kempff's achievement here.
Kempff was famed for his absolute clarity of articulation and his subtlety of touch. His approach was very classical and this variety of touch giving variety to his phrasing was never at the expense of maintaining a tight rhythmical control. Furthermore he never exceeded the tonal limitations of the piano so there are no examples of undue heaviness, twanging strings or thumping foot pedals.
One consistent oddity to his Beethoven concertos and sonatas was a tendency to play the slow movements at a slightly faster tempo than was usual thus creating a forward sense of flow. The outer movements were often slightly steadier than was usual so, coupled with his rhythmic control and light touch, these movements dance more joyfully than usual. I have always been convinced by this readjustment of tempo balance within works.
All of this is to be found in abundance in these readings, both in the concertos and in the sonata.
The orchestral balance is more perfect than is often the case. Every one of the woodwind's crucial dialogue phrases with the piano and with each other are clearly audible as are the string's rhythmical accompanying chords etc. This perfect blend is due to a combination of faithful recording balance, good conducting and sensitive pianism.
The sonata recording is drier and for that reason I have always preferred the sound of his earlier mono set. Nevertheless the performance still remains as outstanding as the concertos although it will be for the concertos that this box set will most likely be bought.
I have always found these discs to be a joy from start to finish. To paraphrase The Gramophone from years ago I would suggest that to hear Kempff playing Beethoven is like listening to Beethoven speaking to us directly without an intermediary. Kempff playing Beethoven was a very special talent and we are lucky to have such fine recordings of it. I would suggest that this set should therefore warrant serious consideration from all lovers of Beethoven's piano concertos and collectors of fine piano playing. There are others though who prefer the set with van Kempen conducting so I would suggest trying to listen to both sets first before choosing.