Okay I'm weaning myself OFF the Grateful Dead this week (but slowly )
This one is a concert where they invited The Allmans in, specifically Dicky Betts on joint lead playing in the middle channel, with classic rhythm guitarist Bob Weir left channel, with
Jerry Garcia taking the right channel playing here some "bluegrass style licks" (which is interesting going back to his original roots).
Anyways, the real jam starts at around the 6:00 min with Dicky in the middle then about the 8:00 Jerry on the right joins the jam.
That's Alright Mama - Grateful Dead with the Allmans