By Ian Youngs
Music reporter, BBC News
Billy Bragg (left), Mick Jones (centre), Chris Shiflett (back right) and Wayne Kramer. Photo: Peter Stevens
Members of the Clash, the Foo Fighters and the MC5 have united on stage to support a campaign to teach prisoners to play guitar.
Mick Jones of the Clash, Chris Shiflett of the Foo Fighters and Wayne Kramer of the MC5 joined Billy Bragg at the gig.
They played the Clash song Jail Guitar Doors, which is also the name of Bragg's campaign to help rehabilitate prisoners through learning instruments.
They performed after the premiere of a documentary about the scheme in London.
Bragg launched the initiative in 2007 and has so far recruited a string of musicians to take instruments into 25 prisons across the UK.
Speaking before the premiere, he said the results had been "very positive".
"When they come out of prison, we hope that we're giving them a way of processing the problems they face in a non-confrontational way," he told BBC News.
Bragg and his fellow musicians leave donated instruments in institutions for the prisoners, but denied it was a soft option and said the guitars were not simply gifts.
"It's not a present for these guys. When I go into prisons, I make it explicit to them that this is a challenge. People outside have raised money for these guitars because they want you to come back into society.
Former Libertines and Dirty Pretty Things singer Carl Barat is among those who have visited inmates as part of the campaign.
"It was quite an eye opener. Pretty scary," he said. "But as soon as you get over that you realise you can make a difference.
"Music is a form of expression and a lot of people in institutions like this have problems with expression, so done the right way it can give people a voice."
The Clash wrote the song Jail Guitar Doors about Wayne Kramer, the guitarist whose band MC5 were among the early punk rock pioneers.
Kramer is now launching the scheme in the US after discussing it with Bragg.
"I knew the song because The Clash were gracious to write the song about my misadventures as a younger man," he said.
"The more we talked about it, I thought, this is something we need to do in America. There's no downside to it."
Thursday's performance at Proud Galleries in Camden also featured several former inmates who have benefitted from tuition.
Jonny Neesom, 26, served five years of a seven-year sentence for wounding with intent and is now attempting to forge a career as a musician.
"I had a fight when I was younger and stabbed someone," he said. "In the last year and a half, I started learning how to play the guitar but never thought much would come from it - it was just something to pass the time in prison.
"Then I got out and people seemed to like the music and it's gone from strength to strength and I've got gigs all the time.
"It sounds cheesy, but it's kind of changed my life. Instead of criminals, I mix with musicians."