Members of Led Zeppelin, particularly guitarist Jimmy Page, worked hard to make sure that Becoming Led Zeppelin authentically presented their early days.

As Jason Bonham tells the UCR Podcast, he also helped sort out an important detail regarding how his late father, John Bonham, would be represented in the film. “I got to see a version of it a few years ago and the voice was wrong,” he shares. “Probably from the years of them having a tape and it being transferred, there was a slight pitch issue.”
 
 
Bonham’s mother suggested that he watch the film as it was in progress and weigh in with his thoughts. “She didn’t tell me what I needed to look for, [but] she felt the same way,” he recalls. “Obviously, they’re watching me to get my reaction. As I’m watching the documentary, I’m realizing, how are they going to do this? Because everybody’s narrating their own story and my dad’s not around. So there was an anxiety when he started to speak and I welled up.”

Hearing his dad’s voice, Bonham heard that it was slightly higher than it should have been. “Oh, that’s weird, I don’t remember him sounding like that,” he thought. “At the end, they went, ‘We looked for the reaction and we were surprised.’ I said, ‘Well, that’s not him. The voice [has changed with] the translation between tapes and copies. You need to do your research a bit more. You need to listen to the Zeppelin albums, where you [can] hear where the timbre of his voice is.”