Sound the horns and part the streets. Actually, scratch that. Charge the streets. HONK! Festival is back, and it wants you to march alongside it.

This weekend, the sociopolitical music festival returns for its 12th year of rousing brass, percussive spectacles, and challenging complacency in Somerville and beyond. Those unfamiliar with the festival may recall that one year they saw people twirling hoops in the middle of the street while attired in circus costumes. Others may recall the year they heard loud marching band music through their windows. Some may remember seeing lanterns floating in the skies of Somerville. All of those memories can become more vivid if you scurry on down to HONK! Festival, because it plans on bringing back the features that have drawn thousands to the streets to join in on the family-friendly, grassroots fun. After all, it’s completely free to anyone and everyone.

It kicks off on Friday at 4 pm with the lantern making workshops at Hodgkins Park in Davis Square, where people of all ages are invited to make DIY lanterns for free. Come 7 pm, attendees can light their lanterns with bike lights, safe candles, flashlights, and more along the sidewalks of Davis Square. Once 8:30 pm hits, a handful of the HONK! bands will perform at ONCE Somerville with beer served by Aeronaut Brewing Company. On Saturday, the festivities reach their peak with the official HONK! Festival in Davis Square. From noon until 9 pm, more than 25 activist street bands from around the world will perform outdoors for free. On Sunday, the HONK! Parade will descend down Mass Ave from Davis Square to Harvard Square to “reclaim the streets for horns, bikes, and feet,” which is more celebratory and giddy than you can imagine. Once they reach Harvard Square, the HONK! bands will perform on the main stage of the square’s Oktoberfest until 6 pm. If you’re still hungry for more, pregame it all by heading over to Lowell on Thursday for the pre-HONK! Brass n’ Bike show where a bike ride at 5 pm will preface a 7:30 pm concert organized by the Party Band.

It’s a lot to take in. We get it. So let’s break HONK! Festival down into the three things that make it unique. First is the fact that everything is free, from Friday night’s performance at ONCE Ballroom all the way down to the street performances. Second is that it’s noncommercial. It doesn’t charge vendors to use space at the events, a decision that most nonprofits lean heavily on. Third is the fact that the festival is aiming to create change beyond music. According to the organizers, it’s about bands who are in it to make positive change in their communities, and that shines through.

“These combine to give it a different vibe, so it really is about the music,” says Ken Field, a member of the HONK! committee and musician in Second Line Social Aid & Pleasure Society Brass Band. “There’s a passion behind the music that drives these people playing it. Not that other bands play music for other, wrong reasons, but that the reason behind these community-based groups is deeper. They’re often diverse in things like age or gender. They aren’t dependent upon musical background. There’s a freedom to it. Because of that, it winds up being different from most other music festivals.”

There are plenty of acts representing this vibe. Boycott, aNova Brazil, Dirty Water Brass Band, Emperor Norton’s Stationary Marching Band, Rara Bel Poze, School of HONK, and Second Line Social Aid & Pleasure Society Brass Band will represent the greater Boston brass scene at the festival. But it’s some of the traveling acts, like Yes Ma’am Brass Band from Austin or Brass Liberation Orchestra from San Francisco, that make the festivities so thrilling.

We’ve got our sight set on Damas de Ferro in particular. The all-female band hails from Rio de Janeiro, Brazil. Damas de Farro believe in the empowerment of women through feminist protest and infusing their musical identity with a lively repertoire brings their name—which literally translates to Iron Ladies in English—to its full metal potential. Boston streets turn into a multicultural activist platform in their hands, and witnessing that live should be a reminder of what we can all do with what we are given—and what we want to fight for.

“Part of the concept of the HONK! Bands is that they’re performing in public space,” says Field. “We’re encouraging people to make use of public space. Go outside. Make noise. When that public space happens to be a street for a parade, we phrase it in those ‘reclaiming’ terms to remind people to take advantage of resources.”

HONK! FESTIVAL. FRI 10.6–SUN 10.8. VARIOUS LOCATIONS. CAMBRIDGE, SOMERVILLE, AND BOSTON. 12PM/ALL AGES/FREE. HONKFEST.ORG