Jake Cowan’s review published on Letterboxd :
An impromptu, Chopin—aptly played by a young Hugh Grant, holding his own in the overpowering presence of the Judy Davis as the scandalous but fierce George Sand—should conceal its careful clockwork artistry so as to appear utterly spontaneous, unpredictable, and lively. It's a shame, then, that IMPROMPTU feels so often so forced, so rarely alive with the genius the film is filled with, more like a meticulous and thoughtful exercise for nimble fingers than a performance stoked by a spark of genius. The elements and personages are here for something much more passionate and moving, truly great painters (Delacroix) and writers (Sand/Alfred du Musset) and composers (Chopin/Liszt) populating every scene, but the film too easily uses their talent to dress up its love story rather than dwelling on their art, their creativity, their aesthetic struggle in any significant way. The movie is rather explicit that only Chopin's work matters here, even as the frail pianist himself is secondary to Sand, her own novels quickly cast aside and her renegade habiliments and habits neutered. So while this is a story that belongs to Sand—a life likely more interesting than any of the rest of her circle—it is Chopin who, by virtue of his immortal genius, becomes the star: A strange sort of cinematic fugue that unfortunately runs counter to the simplicity and clarity of Chopin's actual musicality.