This fanciful biopic casts light on Mozart’s older sister Maria Anna “Nannerl”, a fine singer and instrumentalist in her own right whose ambitions naturally took a backseat to the boy wonder’s prodigious gifts. Based in part on the correspondence of their demanding father Leopold Mozart, the account is a quintessentially French one set in the 1760s when the children are aged 10 and 15, following the imagined events that unfold during performing tours to Paris and Versailles.

Nannerl’s journey centres on two fictionalised encounters with French royalty. The first, with the cloistered, illegitimate 12-year-old daughter of Louis XV, echoes the tragedy of her own thwarted potential. As Louise de France, Lisa Féret is blandly benign and monochrome, making it difficult to care about the rapport between the two young girls, who are in fact real-life sisters.

Meanwhile, the teenage Nannerl’s sexual awakening becomes a focus with the help of the brooding Dauphin’s smouldering gaze (Clovis Fouin). The attraction is inextricably linked with his intense admiration of her music, freeing her creative spirit – temporarily, at least. She is forced to dress as a boy in order to consort with the prince in public, but this narrative tool, again designed to emphasise...