1. Cover plate: two cover plates are installed on the upper and lower sides of the harmonica to protect the reeds, which are combined with the plastic lattice to form a resonance box.

2. Bottom plate: two thick copper plates are installed on both sides of the plastic lattice, and the vibrating spring of the harmonica is installed on the bottom plate.

3. Reed: arranged on the bottom plate, made of metal, thick and long to make the sound lower, thin and short to make the sound higher, and sound through the vibration of air inhaled by blowing.

4. Plastic mesh: There are many plastics sandwiched between the bottom plates to form many small mesh holes, and each hole is aligned with a reed to make a sound.

Second, the scales of harmonica are divided into bass, alto and treble.

Bass from two points of bass 5 to one point of bass 5;

Mid-range from 1 to1;

Treble from treble 1 to treble 7.

At the bottom of each box, it says blow or suck, and it is replaced by symbols. "0" is the blowing sound and "X" is the inhalation sound. As can be seen from this table, 1, 3,5 is blowing sound, and 2,4,6,7 is sound absorption.

We put the bass part on the left and the treble part on the right, which is the arrangement of scales in general musical instruments. In order to avoid holding the piano upside down, please find a mark on the piano yourself. For example, the name change mark on the front of the piano box is different from the pattern on the cover. Another example is the screw of the upper cover plate, one side is a nut, the other side is a nut and so on.