Pitt had a lot of time on his hands while making the film, and when he stumbled across his castmate's guitar he started strumming.
"I play guitar and I wasn't working and I wanted to play so I grabbed his guitar and started playing it," the actor recalls. "He came back in and almost yelled at me."
Shaken Pitt apologised and Joaquin showed him why he was so upset: "He opened up the guitar case and inside he opened up this piece of paper and inside was kind of, like, powder," the actor recalls. "I go, 'What is that?' and he goes, 'That's Johnny Cash!' It was some of his remains!".
"It was one of Cash's guitars, I'm not sure which. I'd probably yell at anyone if they touched it. I think the estate or the family had given Joaquin that inspiration to play Johnny Cash."
Phoenix was preparing to play the country music legend when he filmed "The Village" in 2004.