Nocturne is a unique genre of romantic music. It usually refers to a short lyrical instrumental music with a tranquil temperament and a contemplative character. Most of them are piano music. The first person to write this kind of work was the Irish composer John Field in the early 19th century. Field's nocturnes are elegant lyrical pieces with sentimental content and simple and plain form.

Based on Field's work, the Polish composer Chopin improved the artistic level of the nocturne, expanded the scale of the work, and enabled it to express deeper thoughts and feelings and richer artistic conception. Comparing Chopin's Nocturne in A flat major with Field's Nocturne in B flat major, it can be seen that Chopin was obviously influenced by Field; but the images expressed by Chopin are much richer and the poetic meaning expressed is much richer. Much more profound.

Among the accompanying music written by the German composer Mendelssohn for Shakespeare's comedy "A Midsummer Night's Dream", there is a "Nocturne", which is an orchestral piece played between the third and fourth acts. song. This nocturne describes a quiet forest scene at night and uses only woodwinds, horns and string instruments. The whole song is divided into three parts. The quiet and calm melody in the first and third parts is played by the French horn. The sound of the French horn is like a hunter's horn, so it is often used to depict forest scenes. The middle section consists of strings and woodwinds developing the theme of the first section. The string instruments repeat a rhythmically balanced triplet pattern to describe the rustling of leaves in the forest. When the horn blew the first part of the melody again, this sound pattern continued until it finally disappeared into the darkness of the night.

The three nocturnes by French composer Debussy are also orchestral works. These three nocturnes are three colorful music paintings. The title of the first nocturne is "Clouds", the second is "Festival", and the third is "Water Monster". Debussy was an Impressionist composer. Impressionism is an art movement that emerged in the second half of the nineteenth century. The characteristic of Impressionist art is that it focuses on expressing momentary impressions rather than expressing clear ideological content. Impressionist writers reflect the real world based on subjective impressions. Artistic images are like looking at flowers in the fog, hazy and erratic. Impressionist music, like Impressionist painting, focuses on expressing changes in natural light and color, thereby creating a realm of bright tones and vivid charm. But the outline of the artistic image is vague. Of course, Impressionist musicians cannot directly use external light to depict objects like Impressionist painters; they mainly rely on the means of harmony and orchestration, that is, they use the changes in light and shade of timbre and harmonic color, as well as changes in density and shade to reflect light. and color changes.