In its prodigious diversity, a blend of lightheartedness and sharpness, elegance and severity, Mozart’s music is the mirror of his life, which was marked by a succession of harrowing crises and wonderful breakthroughs. Moreover, he himself said he was constantly torn between anguish and joy. In 1778, while he was staying in Paris and in a sad and sombre mood, Mozart composed several piano sonatas, including the dramatic K.310 Sonata, written in that key of A minor which Alfred Einstein said was the key of desolation, the celebrated K.331 Sonata, in the French style and ending famously with its joyous rondo Alla turca (with a coda added in 1784), and the K.333 Sonata over which hovers the shade of Johann Christian Bach, youngest son of Johann Sebastian, to whom Mozart was bound in sincere friendship.

Completed on 20 May 1785, the tragic Fantasia in C minor, K.475, was published under Mozart’s supervision in the same year, together with the Sonata in C minor, K.457. This seemingly free and improvisatory but in fact cleverly constructed work comprises several sections in which lyrical episodes of striking pathos mingle with tormented passages with intense emotional content. The variety of Mozart’s thought and the boldness of his harmonies are here quite exceptional.