Sonata in F major for piano duet, K.497

The F major is the greatest of mozart’s piano-duet sonatas. It is the only one to be dignified by a slow introduction and the first movement has an urgency which is rare in this mainly playful medium. Mozart has not, of course, suppressed his sense of humour, which makes much of the crush note and the repeated notes in the third bar of the main theme of the Allegro di molto. But there is no contrastingly relaxing second subject and, for the first time, an extended development section is concerned with that main thematic material.

The Andante, an imaginatively written dialogue in B flat major, makes an effective contrast with the first movement while retaining, in its 2/2 Andante pulse, something of its momentum. The first subject is basically the property of the primo pianist, who is still more the soloist on its decorated return in the recapitulation. But the second subject is a delightful example of the close contrapuntal relationship between the two pairs of hands.

The last movement, though Mozart gave it no tempo heading, is obviously meant to proceed quite briskly. It is brilliantly and adventurous rondo with most of the enterprise to be found in the primo part but with the occasional surprise, like the syncopated entry just after the introduction of the main theme, in the secundo.