Noctave
The piece
What sets this nocturne, the second of Op. 55, apart is its two-voice writing: over a left hand in eighth notes that undulates in 12/8, the right hand sets a main melody in dialogue with a second voice that answers or accompanies it. There is no change of key signature or tempo: the piece keeps its heading, Lento sostenuto, sempre legato, from start to finish. The text comes from the original printing issued in Paris.
The main task resembles an organist’s: keeping two voices in the same right hand, each with its own legato, dynamics and breathing. Start by playing each voice alone, using the fingerings you will need when they are combined, then put them together. Beneath this duet, more than a hundred leaps carry the left hand from the low bass to higher notes: keep a smooth, circular motion and change the pedal with each bass note. The trills and grace notes of the melody blend into the legato rather than standing apart. Over more than five minutes, keep the sound restrained so the few crescendos have room to grow.