Haydn’s c-minor Sonata is shot through by a passionate, dark, at times sullen mood. It may be regarded as the Viennese classicist’s own “Appassionata” - a great triumph! It is almost inconceivable that its composition stretched over almost ten years, but this interval elapsed between Haydn’s sketch of 1771 and the 1780 first edition.

That Haydn himself regarded the sonata as unusual emerges from a letter to his publisher in which he describes it as the “longest and most difficult” of the six ...