"Slow like a train, sharp like a razor"

That's how June Carter described Johnny Cash's voice, a deep baritone we're all familiar with. We're all familiar with his songs, too, after four decades of the gritty, resonating lyrics that defined Johnny Cash. Now we get to see how the Man in Black became a legend in the new movie "Walk The Line."

"Walk The Line" shows the rise of a musical icon, and the many crashes and burns it took to get there. From Cash's humble beginnings singing along to his mother's hymns in the field to a childhood tragedy and abusive, alcoholic father helped shape the backbone of Cash's personal obstacles.

The film follows Cash to his first forays into songwriting while stationed in the Air Force during the Korean War, and into his struggle to become a musician while supporting his first wife Viv and their growing family.

The film keeps pace like a Cash song: steady and deliberate, laying the groundwork for explosive emotion. It skims over the Cash's baby steps into the music business and the relationship with his first wife Viv, and focuses on the milestones that shaped Cash's destiny, like his audition with Sam Phillips, head of Sun Records, and his first meeting with June Carter.

The film devotes much of its two-hour running time to the relationship between Carter and Cash. First touring buddies, then one-time lovers, June and Johnny continued to stumble into each other's lives over the course of their careers. When Cash's addiction to amphetamines and subsequent violent outbursts on tour threatened to end his career and life, dutiful June stuck with him, helping Cash turn his life around.

In the film, even the music is a character, as it parades across the screen with a who's who of the country music world, from Elvis and Jerry Lee Lewis to Carl Perkins and Waylon Jennings.

Reese Witherspoon is mature and exuberant as the sassy June Carter. Joaquin Phoenix's performance as Johnny Cash is eerily dead-on, with the baritone voice and hard-living emotion of Cash perfectly tuned.

"Walk The Line" opens today in theaters everywhere.