I'd never heard a June Carter song until I first saw the film. Found one of her performances on YouTube and it was like watching the same person. Admittedly she wasn't as good a singer as Cash though
I've written a one man play about the life and death of Gram Parsons. It's a spoken word monologue with songs, as a ghost - moments after he died of a heroin overdose at the Joshua Tree Inn. 24 years old. I couldn't take the Johnny Cash film seriously, but it got a new audience into the music which is no bad thing.
That book is fantastic, his auto-biography. So honest and beautifully written. I would highly recommend that to anyone. What I wouldn't give for a tour bus with a double bed in the back!