Mary McCartney says dad Paul told her “little anecdotes” for her new Abbey Road Studios documentary

Wednesday night was the New York City premiere of If These Walls Could Sing, a documentary about London’s Abbey Road Studios directed by Mary McCartney that will premiere on Disney+ on December 16. For some inside information, the filmmaker, photographer and cookbook author turned to one of Abbey Road’s most well-known regulars: her dad, Paul McCartney.

Speaking to People, Mary says, “I was with him and I was like, ‘I’m going to make this documentary about the history of Abbey Road,’ and he would just sort of give me little tips. It was good! He was mulling it over and he sort of told me little anecdotes.” What Paul wanted to stress, she says, is how important the people who worked there were to the Beatles’ career.

“He was keen to talk about how the people there had helped them—staff, people behind the scenes, engineers,” Mary explains. “He feels passionate about it. I think in the documentary you see how passionate he is about it.”

Mary says her inspiration for the film was a photo taken of her parents in 1977 which shows them walking across the famous crosswalk seen on the cover of the Abbey Road album with a pony.

“I love the picture of my mom going over the zebra crossing. She had a little pony in London … she’s my inspiration,” Mary tells People of Linda McCartney, Paul’s first wife, who died in 1998. While researching the film, Mary says she learned that her mom would “apparently would come around to [Abbey Road] and be like, ‘Could somebody babysit the kids tonight?’ It shows how I grew up there.”