The HONK! Festival mixes music with social activism and presents it in an irresistibly fun fashion.

The brass will crash and the trumpets bray this weekend in Somerville as the 6th annual HONK! festival hits Davis Square commencing on Friday, September 30 at sundown and running through Monday, October 3.

The fun-filled, slightly subversive street celebration brings brass, drums, and almost anything that can make a happy noise together to march and make merriment fit for the entire family.

The event kicks off at Johnny D’s Uptown on Friday night (10 p.m.) with Revolutionary Snake Ensemble, joined by an impressive guest roster of HONK! band members.

The honking goes full bore on Saturday in Davis Square with up to thirty or more street bands from near and far performing outdoors for free.  An opening ceremony will be held at noon in 7 Hills Park, with music following, performed throughout Davis Square, from 1-9 pm.  At this writing the following bands will be participating during the day on Saturday, listed in alphabetical order: AfroBrazil, Brass Balagan, Brass Messengers, Bread and Puppet Theater Circus Band, Caka!ak Thunder, Carnival Band, Chaotic Insurrection Ensemble, Detroit Party Marching Band, Dirty Water Brass Band, DJA-Rara, Emperor Norton’s Stationary Marching Band, Environmental Encroachment, Expandable Brass Band, Extraordinary Rendition Band, Factory Seconds, Forward!/Milwaukee Molotov Marchers, Hungry March Band, Leftist Marching Band, Minor Mishap Marching Band, Open Hand Orchestra, Rude Mechanical Orchestra, Second Line Social Aid & Pleasure Society Brass Band, Seed and Feed Marching Abominable, Springville All Star Marching Band, Titanium Sporkestra, To Be Named Later Brass Band, What Cheer? Brigade, and Young Fellaz.

On Sunday the HONK! Parade to Reclaim the Streets for Horns, Bikes and Feet takes to the streets.

The theme for this year’s Parade is SHARE – sharing the road, sharing skills, resources, and the upbeat HONK! spirit. Led by the Mayors of Somerville and Cambridge, the parade will feature all the HONK! bands, plus the Bread & Puppet Theater, the impromptu “community band,” and many local arts and community organizations, such as Green Streets Initiative, Bikes Not Bombs, 350.org, Open Air Circus, Puppeteers Cooperative, Livable Streets, and Sprout. The parade assembles at 11 a.m., and the route starts in Davis Square, Somerville, at noon, making its way to Harvard Square’s Oktoberfest celebration in Cambridge.

On Monday the HONK!-sters go academic as they present a symposium (“HONK! and Education Symposium: Share the Knowledge”) at Harvard University’s HGSE – Gutman Library (lower level) from 10:00 a.m. to 2:00 p.m.

The festivities wind down Monday afternoon as bands play at Boys and Girls Clubs around the greater Boston area.

Always a crowd pleaser, the HONK! festival is a sure cure for the post-summertime blues. Visit http://honkfest.org for full details.