FantaisieImpromptu

Fantaisie-Impromptu in C-sharp minor, Op. posth. 66, is a solo piano work by Frédéric Chopin. Composed in 1834, it was published after the composer’s death in 1842 by Julian Fontana, who assigned the unpublished piece the opus number 66. Today the work is among Chopin's best-known and most frequently performed compositions.

The piece is written in C-sharp minor and is usually played with a brisk, agitato tempo and a virtuosic right-hand figure of rapid triplets, contrasted with a more lyrical left-hand line. The distinctive texture and momentum contribute to its lasting popularity and recognizability.

Structurally, Fantaisie-Impromptu begins with the lively main section, moves to a contrasting middle section in D-flat major with a singing melody, and returns to the original mood and key for a dramatic coda. It is commonly described as a three-part form with a contrasting central episode.

Reception and influence: The piece has become a staple of the Romantic piano repertoire. It is widely recorded and taught, and its opening theme is widely recognisable; it has appeared in films and other popular media. Its enduring status makes it one of Chopin’s most enduring legacies in concert music.