A communal meeting of punk and folk

“But those bands just drown out the chant once they start playing,’’ Casey notes.

Sarah, Nora, Ariel, and Rose Parkington, though, did not have the firepower to play over anything more than polite applause. They had violins, violas, a few other acoustic stringed instruments, and simple percussion - all arranged around bewitching vocal harmonies.

“They are a stretch from what you usually see with us. But their songs have roots, and you could hear that. They had the crowd eating out of their hands in 30 seconds,’’ Casey says, recalling the Parkingtons’ live debut with the Dropkicks in Chicago.

The Cape Cod siblings, whom Casey saw performing in Wellfleet and enlisted to play on his band’s latest album, were standouts both opening for and accompanying the Dropkicks during this year’s run of St. Patrick’s Day concerts around Boston.

The Dropkick Murphys’ two-night stand at Fenway Park next week and subsequent Shamrock-N-Roll Festival will feature an interesting mix of styles, from the expected squall of punk rock to more introspective folk fare. Next Thursday and Friday at Fenway, the Dropkicks will host a musical extravaganza that early in the day (doors open at 5 p.m.) will include Chuck Ragan, Parkington Sisters, and Old Brigade on an acoustic stage. Meanwhile, Street Dogs, Mighty Mighty Bosstones, and the Dropkicks will crank up the volume on the main stage in the ballpark.

The Parkingtons and Ragan will venture on for the remainder of the tour, joining a local acoustic act from each city where the festival is performed. The Shamrock-N-Roll Festival, which doesn’t include the Bosstones but does pick up Stiff Little Fingers and the Mahones and appearances by boxer Micky Ward, will be at the Bangor Waterfront in Maine on Sept. 10 before moving on to Providence on Sept. 16.

As excited as Casey is about having a raft of acoustic bands playing the Fenway fete and ensuing road show, the Parkingtons, Ragan, and Old Brigade’s Dan Gill likewise welcomed the opportunity to join forces with the punk-rock standard-bearers.

“I never listened to punk rock,’’ says Gill, who pops up as a character in the Dropkicks song “Fairmount Hill’’ and has known Casey since the DKM founder’s boyhood. The Old Brigade has Brian Queally on whistle and flute, Matt Glover on mandolin, and John Coe on guitar playing traditional Irish songs.

For the past decade, Old Brigade has been playing Boston-area pubs and private functions and didn’t really play a big room until the Dropkicks asked the traditional band to be an opener at the House of Blues during St. Patrick’s Day concerts there a couple of years ago.

On his exposure to live punk rock, Gill says, “To see them play, that first time, just got the blood flowing.’’

The camaraderie Gill says his band shares with the Dropkicks underscores how these two musical camps share values - kinship and community, among them - if not volumes, an aspect also noted by the other folk bands heading to Fenway.

“It’s music for the people,’’ Nora Parkington says. “Punk rock and folk music are unselfish and about unity. They both also have working-class roots.’’

The Parkington Sisters, who are readying a full-length follow-up to their EP, “Ours by the Day,’’ have not only teamed with the Dropkicks, but also layered strings into recordings by punk-rocker Brian Fallon from Gaslight Anthem on his roots-oriented project Horrible Crowes.

After several years in the punk outfit Hot Water Music, Ragan turned to acoustic performances during that band’s hiatus. On Sept. 13, Ragan releases the gritty and dry “Covering Ground,’’ his third full-length studio album of acoustic music.

“There are a lot of parallels between the two styles,’’ Ragan says. “And a lot of people don’t realize the amount of acoustic and folk music within the punk community.’’

The emotional output, Ragan adds, can be the same in a punk or acoustic setting.

“We stomp, rage, sweat, and howl at the moon,’’ he says of his acoustic trio.

On “Covering Ground,’’ Ragan sounds possessed, perhaps channeling the folk and gospel he heard growing up in a Southern Baptist household that didn’t allow rock music (let alone punk rock). But amid the sparse arrangements and blasts of harmonica, there’s an authentic yearning conveyed in the music, a quality that is also present in his work with Hot Water Music.

“It’s so cool seeing the power he produced without using any drums. He’ll go through two sets of guitar strings in a night,’’ Sarah Parkington says of Ragan’s live shows.

On a tour earlier this year, the Parkingtons led into Ragan, who preceded the Dropkicks, and the sisters agree that the flow from their ethereal sound to Ragan’s bruised Americana on into the Dropkicks’ Celtic-punk blowout was a great artistic arc.

Casey sees the connection as a mindset more than a sound.

“These acoustic musicians and punk bands want a closeness to the audience. We all prefer as little a barrier as possible,’’ Casey says. “A folk musician will busk right on the street or we’ll be playing to 4,000 people and have as many kids get on stage as we can fit. It’s the same thing.’’

Scott McLennan can be reached at smclennan1010@gmail.com.