Billy Bragg, a self-described “old Clash fan,” will perform at 7 p.m. Tuesday at the Tower Theatre.

‘I write songs about the things that piss me off,” says post-punk troubadour Billy Bragg, speaking to The Bulletin by phone from his home in Dorset, England, prior to a U.S. tour that brings him to the Tower Theatre on Tuesday (see “If you go”).

Known for his political songwriting and enthusiasm for progressive causes, the 52-year-old Bragg says “music is a way of … facing the world in a nonconfrontational way. I’ve come to realize doing this for the last few years, actually, I think that’s how I deal with the world, you know? I write these songs on things I’m pissed off (about). I go out every night, sing the songs, the audience all applaud, and I think to myself, ‘I feel justified in saying that now.’”

To name but a few of Bragg’s songs: “A New England,” “Island of No Return,” “Which Side Are You On?” “Between the Wars,” “Talking Wag Club Blues” and “Accident Waiting to Happen,” with the memorable line, “you’re a dedicated swallower of fascism.”

Through the independent program Jail Guitar Doors, named after an old B-side by British punk band The Clash, Bragg has been putting guitars in the hands of prison inmates.

The ability to create music, he says, is “totally cathartic, and I think that’s what we’re trying to encourage the inmates to tap into.”

Bragg is a self-described “old Clash fan” and has even written a song titled “Old Clash Fan Fight Song.” He began Jail Guitar Doors in 2007, the fifth anniversary of the death of Joe Strummer, The Clash’s idealistic leader.

“I was gettin’ a bit bored of doing gigs where we all got together, old Clash fans, and play the old songs and … looked back to the past,” Bragg says. “I wanted to do something that looked forward, so I was trying to think what, and this came across my desk.”

“This” was a request for help from Malcolm Dudley, a drug and rehabilitation worker who was using his guitar skills to better the lives of prisoners. Dudley was getting good results, but trouble was, he had just two guitars, one of them a loaner from the prison chaplain: hardly enough for the prisoners to practice on between sessions.

“The Clash always tried to give a voice to those people that didn’t have a voice. This seems to be the sort of thing that, perhaps, they might have done,” he says. “So I’m gonna do this in memory of Joe.”

He went out and bought six acoustic guitars and emblazoned them with Clash song titles including “Stay Free” and “Jail Guitar Doors,” and gave them to Dudley.

“As a musician, knowing that playing a music instrument, particularly a guitar, allows you to momentarily transcend your surroundings, I could see how that might be helpful for someone trying to focus their life in somewhere like a penitentiary,” he says.

About a month later, Bragg was to give an award at a music awards ceremony in London, but the band receiving the award was a no-show.

“The (organizer) said, ‘Just talk for five minutes,’” Bragg recalls. “So I just went out and said to the assembled bands and agents and stuff, ‘I’m going to do this thing. We should be doing this as musicians. I’m going to do this, and I’m going to call it Jail Guitar Doors, and I’m sitting at that table over there if you want to come have a word.’”

The first person to come over, hand in pocket, was Mick Jones, lead guitarist of The Clash. “As an old Clash fan, that kind of, you know, sort of seemed to me to justify my faith in the band,” Bragg says.

Since then, more than 20 prisons have received instruments. Bragg says he’s received thank-you letters from ex-convicts, and with support from the likes of Tom Morrello of Rage Against the Machine and Chris Shiflett of Foo Fighters, the program has spread to the United States. “Anybody who’s a musician really can do this … you don’t have be Metallica to do it,” he says.

“I’ve always been committed to trying to use the platform and opportunities that I have to say more than, ‘Would you like to buy my record?’” says Bragg, whose last record, “Mr. Love and Justice” was released two years ago. “I am still engaged with the recording industry,” which “isn’t having the best time at the moment,” he says.

“About a year ago, I started to look at ways in which you can sort of spread the word if you’re not constantly in the media and not played on the radio. What opportunities does an artist have? It’s changed incredibly since I first started,” says Bragg, whose music career began in 1977 with the formation of the punk-inspired group Riff Raff. He’s released numerous albums since the solo “Life’s a Riot with Spy Vs Spy” in 1983.

Bragg says that in the old days he’d try to get ink in publications such as the New Music Express, which “at its absolute peak … was selling 150,000 copies. Well, some of the things I put on Facebook get read by 150,000 people. So there’s a potential there for me to be able to connect with an audience and keep them abreast of my activities in a way that, before, I had to rely on third parties to do for me.”

In fact, he adds, he’d recently been engaged in a Facebook debate about the pros and cons of Jail Guitar Doors and whether “we should be rewarding offenders,” as one skeptic put it, by giving them guitars.

“I’m trying to make the point that, while we have people in our custody, we should be trying to intervene in their lives rather than just locking them up and throwing away the key,” he said.

Bragg says he’s willing to engage in such debate so long as it remains respectful. “The website does occasionally get attacked by representatives of racist, fascist parties I’ve been active against, and I have to delete those posts.”

In addition to the goings-on on his side of the pond, Bragg also follows American politics and the Tea Party movement, or as he calls it, “the armed wing of the middle-class.”

“For someone like me who’s always been interested in politics, these are quite exciting times,” he says. Known for his on-stage storytelling, Bragg says that solo shows like his upcoming gig at the Tower allow him to offer comment on current events.

“With the midterms coming up, I’m sure that by the time I get to Bend, there’ll be some interesting things that have happened in the U.S. in the previous week that I’ll be able to put in a particular song that reflects that particular issue,” he says. “It’s part of what you do. You’re bringing the news from one place and taking it to another place. I’ve always done that.”

If you go

What: Billy Bragg

When: 7 p.m. Tuesday

Where: Tower Theatre

Cost: $26.50-$40

Contact: 541-317-0700 or www.towertheatre.org