Étude Op. 10, No. 4, in C-sharp minor, is a study for solo piano composed by Frédéric Chopin in 1830. It was first published in 1833 in France, Germany, and England as the fourth piece of his Études Op. 10. This passionate study, a very fast Presto con fuoco, features continuous sixteenth notes (semiquavers), in perpetuum mobile fashion involving both hands.