口琴，构造简单，携带方便，是一种通过吹吸而发音的乐器。它上下两格装着同样高度的音簧各一片（上下两格称为一孔），通过吹或吸两格音簧同时发音，音的高度完全一致。 每只口琴只能吹一个调子，比如Ｃ调或Ａ调等等，初学者最好选一只２１孔的Ｃ调口琴。因为口琴是通过吹气和 Harmonica, simple structure, easy to carry, is a kind of musical instrument by blowing suction and sound. It is installed up and down two grids with the same height of the gong each one (up and down two grid called a hole), by blowing or sucking two gongs simultaneously pronunciation, the sound of the same height. Each harmonica can only play a tune, such as C or A tune and so on, the best beginner choose a 21 hole C Harmonica. Because the harmonica is through the air and