Noctave
The piece
Composed in 1834, the Fantaisie-Impromptu was never published by Chopin: it appeared after his death, in 1855, through his friend Julian Fontana. The plan is in three parts: a swirling Allegro agitato, a central Moderato cantabile in D-flat major with a broad, peaceful melody, then the return of the whirlwind as a Presto. In the coda, the left hand recalls the central melody beneath the right hand's sixteenth notes. The text follows Herrmann Scholtz's Peters edition; the piece gives its name to the “Vers la Fantaisie-Impromptu” journey.
The whole challenge lies in four against three: the right hand plays four sixteenth notes while the left plays three triplet eighths, on 238 beats. Learn each hand until it is automatic, then combine them by thinking only of the beats where they meet. The right hand runs at eleven notes per second, with 225 large leaps between its figures; the left unrolls wide arpeggios at more than eight notes per second. In the central section, change your approach: the melody needs to breathe, with a measured rubato.