The piece
Chopin never published this nocturne, and the score used here was entered from his manuscript, without the additions found in printed editions: no dynamics, no fingering, not even a tempo marking. What remains are the notes and the few signs Chopin himself attached to them: some accents, a mordent, a rolled chord, slurs. You will recognise the nocturne manner, a dotted melody over a left hand in even eighth notes; everything else is up to you.
The left hand alternates a bass note and a broken chord across a wide stretch of keyboard: the piece covers nearly six octaves, from MIDI number 31 to 101. Keep that alternation supple, with the bass slightly more present than the upper notes. The grace notes and the mordent are inflections of the voice: do not delay the bass for them. The long run that tumbles down from the treble, under an octave line, is best practised right hand alone. Since nothing is marked, choose the dynamics yourself; Noctave’s note fading then helps you read this bare text from the score alone.