The young musician and composer Josef lives with Beethoven's music copyist in Grinzing. In the evenings, he plays for dances in the Prater, often his own melodies, although he doesn't make much effort to spread them, as they're almost all waltzes, a dance not well-regarded in high society because they're too sweaty. When one evening a lively princess—fresh from the convent—mingles incognito with the Prater crowd and falls in love with the dashing conductor Josef, an entire cultural system of values begins to crumble.