I've used this site for some time. In the forums, I have always found some useful info. I figure it's time to give back to them. This is what I got from watching a youtube vid. It's a basic outline and not meant to be played note for note. I think Jerry is playing the same thing in 1st position or just E. It seemed to me that bob was playing the main riff. you can add notes from the E major scale to spice this up more if you want. Again this is the riff at it's most basic.