BERLIN (Reuters) - The Rolling Stones have been asked when they would lay down their guitars for good ever since the mid-1960s, shortly after they formed.
More than 40 years on, director Martin Scorsese's new concert film of the British band provides few clues, with the veteran rockers rolling back the years and Mick Jagger putting in a performance worthy of a man a third of his age.
Whether the two 2006 concerts in New York where the footage was taken will be among their last is not the point, Scorsese argues, although one reason for making "Shine a Light" was to preserve the Rolling Stones for the future.
"This might give some sense of what it is as a working band on stage for generations to come, hopefully to see this and to appreciate who they are," Scorsese told Reuters after the movie was screened to the press at the Berlin Film Festival.
At 65, the New York-born film maker is roughly the same age as the Stones, and their music provided a soundtrack to his life which he said influenced his work heavily.
"The sound of the Stones, the construction of the songs, the nature of the chords that are used, the sound of the voice, Jagger's voice, all of this worked on me in my own mind from listening to the records," he said in an interview.
He added that the Stones were part of his "musical movie DNA," explaining why the song "Gimme Shelter," for example, had made it into so many of his movies. The music influenced the pictures, not just the sound.
"They certainly influenced the images, there's no doubt about it. Look at 'Mean Streets', it has a similar kind of edge to it. I was attracted to that kind of music and what they were saying at that time."
Scorsese's relationship with rock music goes back a long way. His credits include "second unit director" on the 1970 documentary film "Woodstock" and "montage supervisor" on the 1972 film "Elvis on Tour."
In 1978 he released "The Last Waltz" about The Band and nearly 30 years later "No Direction Home: Bob Dylan."
Scorsese resisted the temptation to make a full documentary of the Rolling Stones, arguing that it would require 10 to 12 hours of film to do properly.
Instead, he said, "let's give you who they are, which is performance, which is why after 40 years they're still performing. That was the idea."
He includes black-and-white archive footage of band members fielding inane questions from increasingly awe-struck reporters, many of which centre around how long the Stones can keep going.
"At a certain point ... the archive ... gives you a sense of the whirlwind nature of performing, continually the same questions," Scorsese said.
"There's no more answering of the questions. The questions are always going to be the same, so what's the answer? The answer is perform, and we're going to show you the performance."
"Shine a Light," out in April, includes appearances by Jack White of The White Stripes, Christina Aguilera and, in one of the film's best moments, blues guitarist and singer Buddy Guy.
Getting enough footage from two concerts required meticulous planning and the use of 17 cameras. The film also includes Scorsese himself, fretting over the song list, and Jagger scoffing at a model of Scorsese's planned set design.
"You might as well have fun with it and use that as the humor of the situation, because it is absurd, to try to get them on the stage with us with our cameras," Scorsese explained. "It was a wonderful circus."