The story told about that version of Hey Jude (maybe true, who knows) is that Pickett was recording an album in Muscle Shoals, AL in 1969 with Duane as the guitarist. When the crew went to get lunch, Duane & Wilson stayed in the studio because, even with the big music scene in Muscle Shoals, mixed groups with Black men & long hairs weren't exactly welcome in a lot of places. When everybody got back to the studio Duane & Wilson were just messing around with the song & it blew everybody away & the final recording became the big track on the album.
A couple of months later in an interview Pickett said: “He stood right in front of me, as though he was playing every note I was singing,. And he was watching me as I sang, and as I screamed, he was screaming with his guitar.”
Duane also played as a session musician on several of Aretha Franklin' Otis Rush albums.