How are the scales of the blues harmonica distributed?

This is the ten-hole harmonica with the most standard scale arrangement, which is called Mi Zu Ki system. It is estimated that 99% of people who love 10 hole harmonica all over the world choose it, with a single reed, two notes for each hole, ***20 notes, about 3 octaves. Generally, a ten-hole harmonica has a * * feature, that is, there is no F(Fa) and A(La) in the bass part and no B(Si) in the treble part, which is specially designed for harmony. Players can still use the bending technique to play the missing scales. In fact, the design of this scale can be traced back to 1825, when richter, a Bohemian musical instrument craftsman, improved and innovated this scale arrangement system. When playing, a group of sounds of 1, 3 and 5 are C chords; when inhaling, a group of sounds of 2, 4, 6 or 5, 7, 2 and 4 are G7 chords, which is very suitable for playing folk music at that time, especially rich in blues.

Refer to Baidu Encyclopedia, "Ten-hole Harmonica" entry.