The instrumental "Night Music" of the 18th century, intended to be played in the open air, was the origin of the Nocturne form. Mozart and Haydn both composed Notturni for various ensembles. However, it is John Field who is considered to be the creator of the Nocturne for piano. Chopin held him in high esteem and often made his pupils work on Nocturnes by this Irish pianist and composer so that they should learn the art of legato and develop a good tone.
Frédéric Chopin composed 21 Nocturnes. The year of composition of each Nocturne cannot always be ascertained, but their publication dates provide exact references. Three Nocturnes were published after his death. Chopin had the soul of a Romantic, and the music of his Nocturnes express his feelings. The atmosphere of dusk is indeed extremely propitious for tender outpourings, melancholy sentiments and musical and poetic improvisations, as in the dialogue between the Muse and the Poet in Alfred de Musset's Nuit de Mai. While maintaining a classic form (generally the ABA lieder form), Chopin moved away from mere romanticism and elevated the nocturne form - his inspiration and pianistic sense made use of Italian bel canto influences to amplify the melody and develop it in expressive ornamental variations, often chromatic. The harmony became more refined and more audacious through the use of dissonances and the accompanying bass lines, in the form of arpeggios or broken chords, more ingenious.
Chopin's Nocturnes contributed greatly to his fame and in spite of the technical difficulties of some of them they seem to provide a good introduction to the knowledge and study of his other works.