The series finds McCartney reacting and reminiscing while he and producer Rick Rubin comb through master recordings and outtakes from Macca's six-decade.
The latest trailer focuses largely on The Beatles, with McCartney praising bandmates John Lennon, George Harrison and Ringo Starr at different points, recalling some of their most exceptional contributions to the band.
But Rubin also takes Sir Paul by surprise by having him react to a quote about his accomplishments.
"Paul is one of the most innovative bass players that ever played bass, and the stuff that's going on now is ripped off from his Beatle period," Rubin reads from a note card. "He's a great, great musician."
"Did I write that?" McCartney replied.
"That's John Lennon," Rubin said.
"That's John! (Laughs) I hadn't heard that," McCartney admitted. "That's beautiful."
McCartney 3,2,1 arrives on Hulu July 16.
Watch the new trailer via the player above!