Okay, I may keep this thread going until I get it down. I have listened to the '64 version and the later live version with the Marshall amps on stage. Different things going on. IN the original '64 version, for the intro Cropper is hitting that Bb triad in the treble register...with the Bb in the bass, not over an F....and that is the only chord he is hitting while the bass is playing the F-F-Ab-Bb. The reference to a Bb triad over an F in the first two posts got me confused???? There is no F under that Bb triad. The bass is playing a Bb. In the later live version, he doesn't play the same thing. HE is hitting an F chord, and Ab and a Bb in time with the beat on those bass notes. I may have to admit/confess to getting a bit complex with my analysis of the rhthym chords going back to a quick stab on the Ab after the Bb. Mea culpa....although it might work..might not.