It's difficult to underestimate the significance of The Clash in rock 'n' roll. They belong on any serious list of the top five rock 'n' roll performers of all time, and their 1979 masterpiece London Calling belongs on any list of the top five albums. But beyond that, do we know who they were? Julien Temple's new documentary Joe Strummer: The Future Is Unwritten attempts to answer that question, although if you want to know more about Mick Jones, Topper Headon or Paul Simonon, it'll have to wait for another movie. This is Strummer's world, and we all just wish we were living in it. The movie begins, like any biography, with Strummer's parents. His father was a diplomat that moved from country to country; Strummer was born in Turkey as John Graham Mellor, and later insisted on being called "Woody" before adopting his legendary moniker.

The singer, songwriter and guitarist attended art school, lived as a squatter in an abandoned London flat and busked on the street before forming his first band, a rockabilly unit. But when he saw the Sex Pistols play, he decided to move in a different direction. The Clash was born, and with it a series of extraordinary shows and five great albums. But only the movie's first hour is dedicated to the Clash. As Strummer intones on the soundtrack, they made every conceivable mistake: success went to their heads, too many drugs, etc. They even made up a few new ones. The band grew successful, they began squabbling and they lost their direction. Temple includes a terrific sequence in which he intercuts two performances of "White Riot," one from a small club in 1977 and one from a giant stadium in 1983, brilliantly illustrating how big they grew and how far they fell.