The guitar is playing in the key of E. Sonny is playing an A harp in 2nd position. Good luck it is a rather easy tune to play, have some fun with it!
Very nice, C.A.!
Taking your brotherly advice, I picked up my Spec20 A, and found the tune both easy and fun to play along with!
Thanks too for NTSH for posting it!
Keep On Harpin'!