Noctave
The piece
The twenty-four preludes of Op. 28 run through every major and minor key, each followed by its relative minor: C major, A minor, G major, E minor, and so on. Chopin finished them in Majorca during the winter of 1838-1839. The fourth rests on an idea pared to the bone: a melody rocking between B and C above repeated chords whose voices slide down slowly, half step by half step. It was played on the organ at Chopin's funeral in 1849.
The left hand carries almost the whole score: repeated eighth-note chords in which only one note changes at a time. Leave the fingers that do not move resting on their keys and shift only the one that steps down; that almost imperceptible slide is what the listener should hear. With 15% of the notes altered, read each chord slowly before playing it. In the right hand, the long notes must sing over a pianissimo accompaniment. At the peak the music quickens and the melody takes on a turn, then falls back. Respect the silence before the last three chords: it is part of the music.