A documentary about the life of legendary rock musician Joe Strummer - most famous as the lead singer of The Clash - opens in the UK this week.
Interviews with Strummer's old bandmates are the heart of the film
Directed by Julien Temple, a friend of Joe Strummer, The Future Is Unwritten combines previously unseen interviews with Strummer - who died in 2002 - and frank conversations with those who were close to him.
Temple, who directed the David Bowie film Absolute Beginners and last year's Glastonbury documentary, told BBC World Service's On Screen programme that he believes the Strummer film illustrates how the artist used his music to convey his political convictions.
"I think it's in his attitude, and his way of thinking and being, that Joe means more than most people in that field," he said.
"He changed many people's lives, and showed them how to live. I think he used fame to really convey good ideas, rather than big himself up."
Temple said that while the musician had been alive, making a film about him was "the last thing I thought I'd do".
But after Strummer's death, many of his friends had felt "lost" and the director realised that his life had not been properly celebrated.
"I thought I could do a film, as that's what I do," explained Temple.
Temple learned a lot about Strummer from a box of old photos given to him by Strummer's wife, Lucinda, including how it had been apparent from an early age that he would be a star.
Lead singer of iconic punk band The Clash
Also sang with The Mescaleros and, briefly, The Pogues
Presented London Calling for BBC World Service
Wrote music for films such as Sid And Nancy and Grosse Point Blank
Died of a congenital heart defect in December 2002
"I've never seen someone so photographed. At school, you could tell he had a great sense of directing photographs of himself - he'd stick his feet up on the desk and get the kid to shoot past his feet in foreground," Temple said.
"He'd always be the centre of the eyeline in photos."
In shooting the documentary, Temple sought to involve a lot of people who were close to Strummer.
He pointed out that as well as the Clash, Strummer had been lead singer with two other bands - The Mescaleros and the 101'ers - and also performed frontman duties for The Pogues in 1994.
Temple made the deliberate choice of setting many of the interviews captured for the documentary around a camp-fire.
"When you make a film like this, you've got to deal first off with the curse of the talking head, and in particular, the wrinkly old rock star," he said.
"By the fire, you half-obscure their faces in flame. They're dark and get the flicker of light across their features - it's much more magical and interesting visually.
"But more than that, it lulls them into talking in a different way, because they get lost in the fire.
"Most importantly, I think it was because it was such an important part of Joe's last few years - he saw it as a way of bringing people together, sat around the fire."