Directed by James Mangold, starring Joaquin Phoenix, Reese Witherspoon, Ginnifer Goodwin, Robert Patrick, Dallas Roberts, Dan John Miller, Larry Bagby and Shelby Lynne.

With Hollywood running out of good stories to retell, real-life biopics are fast becoming the dramas of choice for the big studios. And it's easy to see why: in many cases the histories, usually troubled, of the subjects are well known and there's no problem with creating credible characters. In a little over a year we've had four musical biopics - 'De-Lovely', 'Beyond the Sea', 'Ray' and now the Johnny Cash biopic 'Walk the Line' - all containing triumph, despair and redemption. Of the four, 'Walk the Line' is easily the best; poignant and uplifting without ever being too flashy and driven by two stars who, like the people they play here, seemed unlikely for each other at the outset but turn out to be great together.

Bookended by Cash's seminal concert at Folsom Prison in 1968, 'Walk the Line' traces Cash's (Phoenix) journey from a poverty stricken and tragic childhood through to his musical beginnings and first marriage and on to fame, the downward spiral with pills and salvation with the help of soulmate and wife-to-be June Carter Cash (Witherspoon). We see Cash as both larger than life and the everyman, trying to walk the tightrope between privacy and fame, with his safety net a woman who, like him, was unhappily married to someone else.

Writer-director James Mangold's career has been a difficult one to graph, containing as it does the low-key ('Heavy'), the under-appreciated ('Copland'), the Oscar-winning ('Girl, Interrupted'), the average ('Identity') and the throwaway ('Kate & Leopold'). But while 'Walk the Line' lives up to its title in terms of biopic conventions, Mangold is concerned with the man, rather than the legend and his unfussy direction means that his film is ultimately more affecting.

Many were puzzled when it was announced that Phoenix would play Cash, but in one of those inspired casting moves it becomes impossible to see anyone else in the part. Ditto Witherspoon, an actress who's always had a lot more to her than some of her choices would suggest and who co-creates a chemistry here that captures a relationship better than most films. Your admiration for the duo grows even more when you realise they both sang the songs onscreen and if 'Walk the Line' sometimes has a little too much music when it could've done with a little more drama (Patrick as Cash's aloof father deserved far more scenes) it's a minor point in a film whose lessons are worth hearing.

June Carter Cash died of complications following heart surgery in May 2003. Less than four months later Johnny Cash died of complications from diabetes. On the liner notes to his compilation 'Love' in 2000, Cash wrote of his wife: "Never has there been a deeper love than my love for her. At times it was painful, but we shared the pain, so it was just half painful." This film is a fitting tribute to them and it.

Harry Guerin