From: "Winslow Yerxa" <winslowyerxa@xxxxxxxxx>
Listening to the chords on a clip of the Stones' version, I hear the main riff being sung over an A minor chord, landing (then vamping) on D minor, which has a feeling of finality and rest.
This tells me that the tune is in D minor, despite everyone saying it's in A.
F - Em - Dm F - Em - Dm Em
Sugar Blue himself claims that he plays the song in second position.
Am Dm Em F Key of Am I IV V vi Key of Dm V I ii iii