Any filmmaker who chooses to condense the colorful life and adventurous times of a larger-than-life historical figure into the cramped confines of a two-hour movie is begging for a thorough caning from film critics and historians alike if the project is botched.

Surely that must have occurred to director James Mangold over the past half decade as he desperately attempted to wrestle the irresistible love story of Johnny Cash and June Carter into "Walk the Line."

And it was a daunting task; the very intimate story of the blossoming passion of the first couple of country music was played out against the expansive backdrop of the turbulent '60s, the rapidly changing profile of country music as a cultural phenomenon and Cash's own self-destructive renegade reputation.

Through it all, Mangold's vision for making the movie version of Cash and Carter's incredibly moving romance remained true. He collaborated with Cash and Carter at the very end of their lives to secure the necessary details to make the eventual film of their love affair even more compelling.

Early word on the moving starring Joaquin Phoenix and Reese Witherspoon (who trained diligently to do all their own singing and performing) has been positive.

Mangold deserves much of the credit for the critical success of "Walk the Line," if only for the intuitive sense of casting that he employed to populate his film.

Mangold hired a number of musical talents to portray a host of Cash and Carter's family and most famous contemporaries, including Shelby Lynne as Cash's mother Carrie, Goober & the Peas/Blanche guitarist/singer Dan John Miller as Cash's guitarist Luther Perkins, country rocker Shooter Jennings as his father Waylon Jennings and singer/songwriter Waylon Payne in a brief but potent star turn as Jerry Lee Lewis.

For Jennings, the fun was in allowing the spirits of our collective musical past to inhabit their physical bodies and to experience some of the wildness of his father's youth without the obvious repercussions. Almost.

"It was one of the best times I'll ever remember and can't remember, all at the same time," says Jennings with a laugh from his tour stop in Shreveport, La. "It was nuts. Most everybody was musicians and singers, and we all have our own little demons. So, we're crazy anyway. And we're all just totally getting into it."

Revisiting his father's era through his father's eyes was a revelation for Jennings as well, especially when he realized just how deeply the party ethic was ingrained into that generation.

"I'm only in two scenes in the movie - it's more of a cameo than anything - but I do get to sing a song," says Jennings. "It was just wild. I remember being scared, but I was having such a good time with Joaquin and Waylon Payne and all the dudes in the movie. We had a blast."

Jennings has a natural connection to the film industry; he lived and worked in Los Angeles for several years, and his girlfriend is former "Sopranos" and current 'Joey" star Drea DeMatteo.

For Dan John Miller, the path to "Walk the Line" was slightly more circuitous.

The Blanche front man and Detroit native has a couple of indie acting gigs on his resume and mentioned the fact to producer T Bone Burnett when he was in L.A. Burnett passed the information along to the casting director, who contacted Miller while Blanche was in Austin for South by Southwest and asked if he would be interested in auditioning for a part.

"She'd heard I'd done some acting and played guitar, and they were trying to get a guitar player for this Johnny Cash movie, which I had never heard that they were making," says Miller from his Detroit home. "I sent them a tape of me singing a Johnny Cash song, and they liked that, and they had me come out and audition. It was really a great experience."

After a few weeks of rehearsal in L.A., the production moved to Memphis for shooting. Miller spent around two months filming his role as Luther Perkins (Miller's wife and band mate Tracee Mae makes a brief appearance as Perkins' wife Birdie) before heading out on a late summer tour with Blanche.

Shelby Lynne's experience was slightly different than a lot of her male counterparts. She spent far less time carousing in her off-set down time, opting to recharge from the daily shoot at her Memphis hotel and sequestering herself from the often rowdy off camera periods.

"For me, being a first timer, I kind of liked being tucked away and not doing anything that didn't have anything to do with me," says Lynne from her California home. "I liked to stay in the feel of the time and the character and stay shut away from everyone else."

Still, Lynne's film debut as Cash's mother Carrie was clearly an exhilarating experience for the country soul singer, whose heart-rending ballad "Johnny Met June" is a highlight of her latest album, "Suit Yourself."

"It was fun. I'd do it again," says Lynne. "I'd read for parts for years, but never did anything. This was the right thing. I'd heard through the grapevine that someone was doing a Johnny Cash film, and I wanted a piece of it somehow some way. I got somebody to start poking around and wound up with an audition. When I read for the part (of Carrie Cash), it was about the only thing left. That was what they were looking for."

It was a fascinating first movie role for Lynne, who subjected herself to make-up (or lack thereof) that would age her 30 years within the time frame of the story arc.

"There was nothing to it," says Lynne. "I just didn't wear a lot. I was kind of pale, a little bit of red lipstick and a lot of piled up hair."

Once she had the part, Lynne did as much research as possible to help her get inside the mind of the Arkansas woman who reared one of country music's most celebrated songwriters.

"I read everything there was, but there wasn't a lot of information about her, and I didn't know any of the family," says Lynne. "I just had to read the books and take from my own female experiences, women I've known, and put two and two together and kind of do her justice."

Lynne's experience of seeing herself in the finished version of "Walk the Line" at the film's premiere was nerve wracking but she's enthusiastic about the movie.

"I was really too nervous to enjoy it, but it came off pretty cool," says Lynne. "I was turned on when I read the script. It wasn't a boring script where you had to use your imagination. It was a good read, and it looks good too. Joaquin and Reese were just killer, and they ' did all their singing and playing, which is pretty impressive."

Like Shooter Jennings, Waylon Payne brought a country music pedigree to the project; he's the son of country chanteuse Sammi Smith and longtime Willie Nelson guitarist Jody Payne. In return, Payne provided a brief, but incendiary performance as a heaven-touched/hellbent Jerry Lee Lewis.

"I met (Lewis) two nights ago," says Payne by cell phone on his way to a Southern California lunch. "Me and my friend Margo went to this concert special in conjunction with the movie, and it was like going to heaven and being with all your favorite people. I walk into a room, and there's Jerry Lee Lewis on the couch - and I'd never met him before - sitting next to god himself, Kris Kristofferson. It was like being in the arms of heaven."

Payne's personal interaction with the Lewis turned out to be even better.

"You know what was so trippy? I'm sitting there, and the Killer's on stage at his piano, and we're all sitting fourth row...if I sound excited, it's because I am," says Payne with a laugh. "So the Killer is just staring holes into me and looking at me, and I'm just soaking it in because I'm like, 'Good Lord, I'm in Jerry Lee Lewis' line of fire.'"

"Now imagine if you can, on a huge movie screen right behind him, the portion of the movie where I'm playing him starts, and my hands start playing, and I start singing his song, and it's 20 miles big behind him, and then he turned around and looked at it up there, and then he turned back around and just looked at me, and it was sweet. I coulda passed out then."

Payne had originally auditioned for the part of Waylon Jennings and got a callback, but in the subsequent time he had cut off his hair and dyed it blonde. The Jerry Lee Lewis part seemed destined to be his.

"They asked me if I could play piano, and I said, 'Oddly enough...'" says Payne. "The past six months before that I had locked myself in this old Hollywood apartment and stayed up all night and played piano and watched things grow in the dark. It was a perfect match."

Payne had a personal reason to want to be involved. His initial connection to Cash was through his late mother, whose recording career was actually launched by the Man in Black, who then returned to give Payne himself the same leg up nearly four decades later.

"My mama was 19, 20 years old, singing in a honky tonk in Oklahoma City in the early '60s," says Payne. "Johnny Cash came through Oklahoma City, and Luther Perkins was a friend of mama's, and they came to the show one night, and John was knocked out by her. Two days later, she was in Nashville and signed to Columbia on John's say-so. He got her her first record deal."

"Oddly enough, I come out here to give it a shot, and my career's not going that great, and mistakes had been made, and I'll be danged if the Man in Black didn't come along again and give me the same opportunity. It was a neat spiritual journey for me to make. It's a nice thing that a man who based his life on being honest and being real is having such an impact. It's almost - if I daresay and forgive me if I offend - Christ-like. He's the only man I've ever met in my life that was exactly what he said he was...Mr. Johnny Cash."

So many films of this nature have squandered timing, talent and opportunity ("Great Balls of Fire" comes to mind) that it's great to see a similar confluence used to such magnificent effect in translating the greatest country love story ever toldSomewhere, Johnny Cash and June Carter are smiling, not because a great movie has been made about them but because they are together, just as they were in this temporal life and now for all eternity.