I'm pretty sure that mick is playing in the wrong key on that @ 3.00 minute harmonica (not harp) solo. Whatever the whole song sounds like a disaster now but i bet if you were in the audience on the night it would of all been awesome..sheer star power overwhelming any critical sensibilities.
Nope, Sir Mick is playing an F harp in 2nd pos -- he´s in the right key. But being knighted doesn´t necessarily help you when you got all of five (5) chords to negotiate. Perhaps a C harp would have made it a bit easier for him.