An online Beatles fan club for and about Beatle fans
I have always loved the denim cap.
He wore it until first days o december 1980, as shown in same pic from Bob Gruen: You can also see some footage of John wearing it while boating, but with the unzipped visor button
Those hats were so common in the 70's I love 'em and glad to see them making a comeback. He always seemed like one of us when he wore that.