Blues harp is not my favorite thing. Traditional blues in general doesn't really do it for me as a genre. But when I stumble across someone who does it so well that the style is irrelevant I know there must be something special going on.
Blues harmonica virtuoso Adam Gussow is one of those people. He is half of the duo Satan and Adam, an award winning scholar and associate professor of English and Southern Studies at the University of Mississippi. He has posted a series of thorough and enlightening videos on YouTube, among many other things.
Adam offers what appears to be a well-thought out approach to playing the blues on his excellent website Modern Blues Harmonica. If you have an interest in this music, as a player or listener, I urge you to check it out.