Joaquin Phoenix was determined to screen Johnny Cash biopic Walk the Line at California's Folsom Prison, after realising it is what Cash would have done.

Phoenix introduced the film and emulated the Man In Black by performing some of his songs to inmates last week (3JAN06).

And he tells MTV.COM the experience "was unbelievable".

He says, "I think it's really what John would've wanted. I was screening the film in different places around the country and in Europe and I'd introduce the movie and just really felt that that's where we should play it.

"So it was an unbelievable experience to go in there."