教学视频
https://www.youtube.com/watch?v=Zc-EcRFrxcA
口琴结构
https://www.themusicstand.ca/blogs/htp-harmonica/parts?srsltid=AfmBOor2lLmftg9KxLvFzc1WLxTf1ugep9qoor5EhGAcaWMPbSznJVzm
https://en.wikipedia.org/wiki/Harmonica
