The four-hand repertoire was certainly not popular during the period that the young Wolfgang Amadeus Mozart and his slightly older sister Nannerl would be placed behind a clavier to entertain audiences with four-hand music. Mozart wrote five duet sonatas and several separate works for pianoforte four-hand. On this CD, the four-hand pieces are Mozart’s two last and most monumental sonatas. They explore the limits of the pianoforte, both literally and regarding sound volume. Mozart did not shy away from giving both players an independent and often complicated and technically demanding part.

Sonata in F, K. 497:Mozart’s way of exploiting the opportunities inherent in the four-hand repertoire was pioneering and led to impressive results. This sonata reminds one not only of his symphonic music and operas but also his sometimes highly virtuosic pieces and concertos for pianoforte.
Sonata in C K 521: Instead of the tight interweaving of the four hands of K 497, this sonata establishes a more competitive relationship
between the two performers. Many are the passages where they
imitate each other (with deviations).
The Sonata in D K 448 similar to the K 521 sonata. Here, too, scores of virtuosic figures are passed back and forth by the performers.
(Source: linernotes of the CD 'Sonatas for four hands'- Il Pulcini - Marie & Veronika Kuijken)