W hen Linda Perry agreed to let the director Don Hardy film her at work in her studio, she had no idea what she was getting into. Perry – the singer, producer and wildly successful songwriter-for-hire – had been friends with Hardy since she scored his 2020 film, Citizen Penn, about the actor Sean Penn’s charity work in Haiti. If nothing else, Perry hoped she might use some of Hardy’s footage as content on her Instagram account: “So he just started showing up and I soon forgot he was there.” After a few weeks, Hardy told Perry he had edited 30 minutes of footage and shown it to colleagues. “He said: ‘We think there’s an incredible documentary to be made here,’” she recalls. “And so I said: ‘OK, go ahead but don’t talk to me about it. I don’t want to know anything.…