In 1968, Tom Murray was a young photographer at The Sunday Times when history landed in his lap.

“Don McCullin, the famous war photographer, said he was going to photograph some pop group and [asked if I] would drive him around,” says Murray with a chuckle. “As we were leaving he said, ‘Bring your camera, you might get some nice snaps.’”

Murray grabbed his Nikon F and two rolls of color film. As they neared the rehearsal room, he could hear music. “I said, ‘Somebody’s playing ‘Lady Madonna,’” he remembers. “And then I opened the door, and I said, ‘Oh s- – -. It’s Paul McCartney.’”

The Beatles (plus Yoko Ono) were inside, taking a break from recording the White Album. “Is this the group?” Murray asked, to which McCullin replied, “Didn’t I tell you?”

Dissatisfied with their publicity photos, the Beatles had commissioned McCullin for new pictures, and the photo session that followed is one of the most famous in Beatles lore. Known as the Mad Day Out, it captures the foursome in peak playful mode as they gallivant around London — standing in a garden of hollyhocks, goofing on top of a concrete block at the Old Street roundabout, posing on a bench outside St Pancras Coroner’s Court next to an old man who’d fallen asleep while reading the newspaper.