Just keep in mind that there are different ways to play a harp. One is straight harp where you blow into it to get the tonic. The other is cross harp where you suck in to get the tonic. When playing cross harp you will have a different key harmonica then the song is in (usually up a fourth key). I believe this video is cross harp and there are many versions of cross harp. Do some reading up on it. But once you learn, it can be fun.
Buddy Holly Lives!