In this 1963 footage, Big Joe plays an unaccompanied version of "Baby Please Don't Go".
Big Joe was famous for playing a nine string guitar. He added three extra strings to create unison pairs for the first and second strings and an octave pair for the fourth string. His guitar was usually tuned to Open G, (D G DD G BB DD).
I think he plays a Kay Archtop in this clip with a "who knows what" pickup fixed to the top.
Raw Delta Blues at it's most basic. sb