Lisa Marie was 9 when her father’s death occurred in August 1977.

“It was a very private thing for her,” Keough added.

“She would listen to his music alone, if she was drunk, and cry.”

Riley Keough and Lisa Marie Presley in 2017

Riley Keough and Lisa Marie Presley in 2017.Neilson Barnard/Getty

The project was then put off, but Presley’s passing spurred Keough to revisit the project.