You don't have to like Johnny Cash's music to enjoy "Walk the Line," but if you can't see where Cash's struggles and genius come from, the director and actors didn't fail — you just weren't paying attention.

Just as Cash's music transcends musical genres, the film encompasses many different plot angles. It could have gone deeply into many directions, examining his tenure with the Air Force, how he dealt internally with his seemingly quick jump into fame or his drug addiction to amphetamines and barbiturates.

Instead, the focus is on his relationships with other people. The film unfolds chronologically, beginning with his childhood. Seeing an innocent Cash played by a wide-eyed child actor lends to the believability of his inevitable downfall.

His alcoholic father, played by a stoic Robert Patrick, believes that Cash's brother Tommy is the only sibling destined for fame, which falls hard on Cash throughout his life.

Joaquin Phoenix, handpicked to play the adult Cash by the musician himself, helps move the story along with every sneer and dead-on note. Phoenix learned the guitar from scratch, as did Cash, and performs the songs himself. Initially all of the songs were moved one half-step up in key to accommodate Phoenix's voice, but eventually he mastered Cash's signature baritone. Almost every waver in Phoenix's voice and every mannerism radiates authenticity.

Cash stumbled into fame, recording an album to make money for rent and to support his wife and two children, not because he or even anyone else necessarily believed in his talent. Because of this, one of the highlights of the film is watching Elvis and an overly animated Jerry Lee Lewis talk backstage to Cash in the movie.

Cameos involves not waiting for semi-famous actors to grace the screen with their presence, but rather the ghosts of country music past. Waylon Jennings' character is played by his son and Roy Orbison's character is played by the son of Nelson's longtime guitarist.

The radio has an omnipresent quality, as the young Cash listens to an equally young June Carter (Reese Witherspoon), the "matriarch" of country music on the radio. The radio also creates a plethora of fans in towns the tour caravan has not yet been.

He begins every performance with an unassuming, "Hey, I'm Johnny Cash," and then proceeds to back up his name with his music in a variety of settings, including a prison.

With only his drinking buddies on the road to keep his head level, he becomes a womanizer and has no shame in barely hiding it. This, combined with drug use, leads to part of his tour being canceled and makes him the classic anti-hero.

It is not until he falls hard for June that he wins the audience back. Phoenix and Witherspoon's harmonies complement their clear energy. He does not hide his affection for June from his wife either, and eventually she leaves him and takes the children.

Witherspoon falls into the role perfectly; a sweet southern accent and spunky personality need no explanation as to why Cash fell hard for her. She appears to like Cash because of her altruistic personality and his willingness to help her with the public scorn of her divorce.

Some points in the story seem rushed, as Cash's backup band — the Tennessee Two — suddenly becomes a trio when a drummer is inexplicably assigned to the band.

The movie started filming while Cash and Carter were still alive, and Cash told director James Mangold, "If you're going to make anyone in this movie look bad, it should be me."

Mangold's intent was to show "what it's like to be a rock star when no one has been one before," he said in a featurette for the movie. He depicts all of the peaks and crevices of Cash's life, but eventually Cash's life validates himself, as he stays with Carter until she died. He died four months later.

The film ends as their love situation is finally resolved, solidifying the movie's purpose of gracefully exposing the complicated love story and not the other extraneous plots.

Grade: AB