The phenomenon known as the Sturm und Drang figures prominently in most twentieth-century accounts of Haydn's development as a composer. Théodore de Wyzewa, writing in 1909, was the first to suggest an ‘extremely acute crisis’ in the composer's personal life, in the year 1772. This ‘crisis’, according to Wyzewa, manifested itself in a series of unusual minor-mode works, including Symphonies Nos. 44 (‘Trauer’), 45 (‘Farewell’) and 49 (‘Passione’), and the slightly earlier (1771) Sonata No. 33 in C minor. Wyzewa could not, however, identify any particular incident that would have caused such a ‘Romantic paroxysm’, so he invented one. These minor-mode works were ‘songs of sorrow’ occasioned by the death of a young woman. But ‘without a doubt’, Wyzewa concluded, the world would ‘never know the name of Haydn's “immortal beloved”’.

No one has ever taken Wyzewa's theory of an ‘immortal beloved’ for Haydn very seriously for the simple reason that there is no evidence to support it. Even Wyzewa himself seems to have found this hypothesis insufficient, for he went on in the same essay to offer a second, complementary explanation for these unusual symphonies. The ‘melancholy seriousness’ of these works, he argued, was also at least in part a product of the Zeitgeist and could be found in contemporaneous music by other composers as well, including Gluck, Mozart, C. P. E. Bach, Vanhal and Dittersdorf.