Timothée Chalamet behind the scenes as Bob Dylan in "A Complete Unknown."Macall Polay/Searchlight PicturesTimothée Chalamet portrays Bob Dylan in James Mangold's new film "A Complete Unknown."He spent five years preparing for the role, which included learning to sing and play guitar.Chalamet performs live throughout the film, instead of using prerecorded vocals or instruments.Timothée Chalamet went method to play Bob Dylan for James Mangold's new biopic "A Complete Unknown" — an immersive, yearslong exercise that saw the actor hone his singing voice, learn to play guitar, and even master the harmonica."A Complete Unknown," which arrived in theaters on Christmas Day, follows a young Dylan in the early 1960s as he embeds himself in (and later extricates himself from) the Greenwich Village folk scene, alongside other real-life legends like Joan Baez and Pete Seeger.Chalamet is joined by Monica Barbaro as Baez, Edward Norton as Seeger, and Boyd Holbrook as Johnny Cash.