Noctave
The piece
The first of the eight-bar exercises in Op. 821 is a run of sixteenths for the right hand, played forte. The motif turns around a note before slipping down a step, and this pattern travels more than two octaves toward the bass; it then climbs back in broken figures, with C-sharp and G-sharp, up to the very high A, before a scale brings it down again.
At six notes per second without a break, the right hand gets no rest: every finger has to sound as clean as the one before it. The motif slides downward in a regular sequence; once you've found the fingering for the first group, keep it for the next ones, since it repeats almost unchanged. The climb back up changes figure and accidentals and needs its own fingering, worked out slowly. The left hand only places short chords, mostly on the first and third beats. Start at a reduced tempo, then work up in stages toward 88 beats per minute.