Francis Ford Coppola tells Diane Keaton 'why on Earth' he cast her in The Godfather

Never ask me about my business, Kay...though if you're Diane Keaton, you can ask director Francis Ford Coppola anything you want.

On Friday, Coppola hosted an AMA on his Instagram stories, inviting fans and followers to ask him questions about his work and his life. Keaton, who played Kay Adams-Corleone, the wife of Al Pacino's Michael Corleone, in The Godfather, hopped online to ask Coppola about his casting decisions.

"Why on Earth did you choose me for The Godfather?!!" she wrote, with Coppola noting that Keaton sent in the question since Instagram makes a sender's identity anonymous in a response.

courtesy everett collection Diane Keaton in 'The Godfather'

Coppola shared his answer, explaining that he hit on Keaton's ineffable, quirky quality that has made her a star for decades. "I chose you, because although you were to play the more straight/vanilla wife, there was something more about you," he wrote. "Deeper, funnier, and very interesting (I was right)."

He also shared that he first saw Keaton in the original Broadway production of Hair, which he attended with Fred Astaire, who he directed in 1968's Finian's Rainbow. "I was invited by Fred Astaire to accompany him to see Hair," Coppola added. "Which he couldn't make 'hide nor hair' out of. You were in it, and I remember your beautiful singing voice."

Keaton's first professional job was as a member of the cast of Hair, but it was her work as Kay Adams-Corleone in The Godfather that proved to be her Hollywood breakthrough. She went on to reprise the role in 1974's The Godfather Part II and again in 1990's The Godfather Part III, which was recut as The Godfather Coda: The Death of Michael Corleone in 2020.

Coppola also answered questions about some of his favorite films, including his personal favorite of the films he's made (Rumblefish), and whether he'd ever make a fourth Godfather film (no).

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