This is between you and me.
Adam Gussow is a heckuva harp player. Me, I'm OK, too but Adam is one of the special ones.
So here's what the bugger does:
He lays out on YouTube over 40 lessons about how to play blues harp, from very very beginner to certified screamin' funkmonkey, and he does it in a way that pretty much means that if you can see and hear, you'll get it. Probably quickly.
The whole shmoo: tone, technique, equipment, effects and tricks. Whammo. Not all there is but so close to it y'can feel the breeze. Mr. Gussow mentions he thinks a dedicated type could put it all together enough for pro work in about two years. I think he's right.
The lessons are organized, easy to follow and thorough. I've played for maybe 40 years as a pro and semi-pro and I'm quite decent. I learned very useful new-to-me stuff in lesson two.
I'm certainly not going to support competition in my trade by constantly reminding people about Adam's near-total destruction of the market for blues harmonica teachers in the english speaking world. There is no way I will constantly repeat that I've never encountered better lessons, nor will I unfailingly be advising readers that so far in the series a student requires 10-hole diatonic harmonicas in the keys of Bb, C, D and I think F and G. It would be foolish if I repeated further that the Bb will get a person through the first 10-15 lessons or so.
It would only be adding to the damage were I to even occasionally reiterate that it'd be an idea to get a good harp to start, at least the quality of the quite serviceable Suzuki Harpmaster or better. Adam uses Hohner Marine Bands/Model 1896 (not my first choice, but they're good pro level harps).
Bottom line: I teach harmonica and if you want to play well, you don't really need me anymore. I'll be happy to help, but almost everything you'd want to know is in these lessons, and everything you need to know is right out in the open.
There. I've told you.
The blues harp keys to the kingdom are laying out in plain view.
Don't let this news get out.
And don't expect me to remind you.