Chopin composed and published his popular Nocturne in E-flat major in 1833. This nocturne is filled with melancholy.
The main melody is heard three times during the solo piano piece. With each repetition, it is varied by more and more tones and trills. The foundation for the melodic line is provided by the spaced notes in the accompaniment.
The nocturne is reflective until it becomes passionate near the end. The melody begins softly but then ascends to a high register and is played with force, eventually reaching the loudest part of the musical work. Tension increases as the crescendo brightly moves up to the long trill. Then the excitement subsides, ending the nocturne calmly.
If you want to understand and get to know Chopin, you can read his letters.