At a loose end tomorrow afternoon? If you fancy a bit of folk-punk-protest live music, hop on the Northern Line and head down to The Flowerpot in Camden where Billy Bragg will be playing at the Jail Guitar Doors All Dayer.Jail Guitar Doors provides musical instruments to help the rehabilitation of prison inmates. It was set up by the Bard of Barking himself in 2007.That means you're guaranteed an appearance from Bragg at this little Camden venue tomorrow. He'll be playing alongside musicians who've been helped out by Jail Guitar Doors and with other artists involved in the initiative.Bragg's isn't the only name on the bill that you'll recognise. The Rotten Hill Gang will be there along with Mick Jones (formerly of The Clash). And the venue's promised us some other special guests too, though they're keeping schtum about who might turn up.So there you go: Sunday afternoon, a few drinks and the chance to see a national treasure play in aid of a good cause. Oh, and there'll be a barbecue too. What's not to like?Entrance is free and everything kicks off at 2pm. Get more information from The Flowerpot website.