This is an amazing instrumental. It has a cool tuning known as "Cross Tuning". It comes from the world of Old-Time music. Tune one G string to F#. Tune the G string just below that to A. Your courses of D and A strings remain standard. Lastly tune your top E string down to A. Then tune the E string closest to the floor down to D.
Now, you are in tune and ready to play, "Get Up John".