When the members of Fire Fighters Local 311 learned Tom Morello was returning to Madison, Wisconsin, for a Labor Day show, the union men and women asked if they could welcome the veteran Rage Against the Machine and Audioslave guitarist to the city’s historic Barrymore Theatre with the pomp and circumstance accorded a returning champion.

Bagpipes and razor’s-edge rock ’n’ roll?

Madison firefighters and an amplified Woody Guthrie who is featured on the cover of the latest issue of Rolling Stone magazine?

Absolutely. It’s right in tune with the struggle that Wisconsinites have engaged in for the past seven months.

This is the new solidarity, crossing lines of class, politics, ideology and musical genre. And Morello has understood from the day, last February, when he rallied the tens of thousands of protesters outside the state Capitol in Madison. “I’ve played hundreds and hundreds of demonstrations but I’ve never been in the middle of anything like this,” Morello told me the other day, when we talked about his planned return to Madison for the Labor Day show at the Barrymore Theatre with McIlrath, Kramer and other musicians as part of a Justice Tour that will go on to the battleground states of Ohio and Michigan. “The people of Wisconsin are forming one of the last lines of defense against complete corporate control. There’s a vicious class war going on, but only one side was fighting it—the billionaires and the politicians they prop up. There wasn’t a fightback, at least not a sufficient fightback, until Wisconsin.”

Back in February and March, the Local 311 bagpipers were on the front line as they led marches on the Capitol in defense of labor rights and local democracy—and against the corporate cronyism of Governor Scott Walker. For some of the largest protests, they were joined by pipers from across the state who played the ancient instrument of popular insurrection.

Morello’s instrument is different. He plays the guitar, so brilliantly that, with Rage Against the Machine, he won two Grammy Awards and was nominated for five more. He’s been to the top of the Billboard charts with Rage and Audioslave.

Yet his passion remains politics. And, as The Nightwatchman, he’s forged a parallel career as one of the edgiest and most determined movement troubadours this side of Pete Seeger. In February, Morello was one of the first national figures to show up in Madison to join the protests—performing Guthrie’s “This Land Is Your Land” at the Capitol and reading a letter from Egyptian activists cheering on the Wisconsin protests.

In a piece he penned for Rolling Stone, the rocker wrote: “The future of workers’ rights in this country will not be decided in the courts or in Congress, on talk radio or on Fox News. The future of workers’ rights in this country will be decided on the streets of a small Midwestern city, on the streets of Madison, Wis. And who knows? Maybe in your city too. Yeah, this land is our land, and to those occupying the Capitol building tonight, or marching in the streets across the Midwest tomorrow, and to the people still deciding which side they’re on at this historic crossroads, I’d like to pass along some advice from the immortal Woody Guthrie: ‘Take it easy… but take it!’ ”

Since then, Morello has written a great song about the Wisconsin fight—“Union Town”—and donated profits to union groups in the state. And his new album, World Wide Rebel Songs, celebrates street protests from Madison to Cairo.

On Labor Day, Morello and other top artists such as Wayne Kramer of Detroit’s legendary MC5 and Tim McIlrath of Rise Against will launch their Justice Tour of states where unions are battling against right-wing assaults on labor rights. They’re raising money for nonprofit media (via The Nation Institute) that expose corporate abuse and highlights union struggles. But most of all, they’re celebrating the rise of a new pro-labor, pro-democracy movement that marches to the sound of guitars—and bagpipes.