George Thorgood is, to my mind, a kind of hack hype man with a backing band. Did you see Terminator 2: Judgement Day? George Thorgood and The Destroyers did that song Bad to the Bone that is playing early on in that film, I believe after Arnold is done mopping the floor with a bunch of bikers and steals one of their "choppers".
George Thorgood is much how Buzzo described him, someone who has made a living doing covers of old Blues numbers.
His joke about him getting ma-ma-ma-ma-mad is in reference to this Bad to the Bone song in which George sings Ba-Ba-Ba-Ba- Bad to the Bone.