Fantazja-Impromptu in C-sharp minor, Op. posth. 66 by : The C♯ minor sonata, particularly the third movement, is held to have been the inspiration for Frédéric Chopin's Fantaisie-Impromptu, and that the Fantaisie-Impromptu was actually a tribute to Beethoven. It manifests the key relationships of the sonata's three movements, chord structures, and even shares some passages. Ernst Oster writes: "With the aid of the Fantaisie-Impromptu we can at least recognize what particular features of the C♯ minor Sonata struck fire in Chopin. We can actually regard Chopin as our teacher as he points to the coda and says, 'Look here, this is great. Take heed of this example!' ... The Fantaisie-Impromptu is perhaps the only instance where one genius discloses to us – if only by means of a composition of his own – what he actually hears in the work of another genius."