Improved from the traditional harmonica, by using a clever key, you can play the rising and falling semitones on the harmonica. If you don't press the key, it is equivalent to the white key of the piano. After pressing the key, the horse rises by a semitone, which is equivalent to the black keys. There are many famous chromatic harmonica masters in the world, and their performances have been unanimously affirmed and praised by musicians, which shows that chromatic harmonica has been included in the forest of orthodox musical instruments. Chromatic harmonica has been popularized rapidly in recent years. 16 hole chromatic harmonica is often used in harmonica ensembles and multi-ensembles because of its wide range, which can reach four full octaves containing semitones, and it is easy to transpose or tune.

1885, the German Horner Piano Factory developed the world's first 12 hole chromatic harmonica, which is a revolutionary invention. Chromatic harmonica has all semitones with three octaves, which is convenient for modulation, full of sound and changeable timbre. In addition, the gameplay is also constantly enriched. Harmonica can not only play lyrical and soft tunes, but also play difficult solos and concertos like other musical instruments. It soon attracted people's attention to harmonica, and some people began to become professional harmonica players and held concerts widely in Europe and America.