The Nocturnes, Op. 9 are a set of three nocturnes written by Frédéric Chopin between 1830 and 1832, published that year, and dedicated to Madame Camille Pleyel. The second nocturne of the work is regarded as Chopin's most famous piece.
This nocturne has a rhythmic freedom that came to characterise Chopin's later work. The left hand has an unbroken sequence of eighth notes in simple arpeggios throughout the entire piece, while the right hand moves with freedom in patterns of seven, eleven, twenty, and twenty-two notes.
The opening section moves into a contrasting middle section, which flows back to the opening material in a transitional passage where the melody floats above seventeen consecutive bars of D-flat major chords. The reprise of the first section grows out of this, followed by a Picardy third ending.